First of all, I'd like to point out that Feats, Skills, and Magic Items are also not "the heart of classes," they, like alternate class features and racial selections, are options a player has to augment the base class' abilities. I also note that Kalashtar, the race required to use power-linked shards and has a bonus 20pp (not much, but its there), is not off the table, but Kobolds with Draconic Rite of Passage, Loredrake, and Dragonspawn all are. Thus, for the purposes of this thread, one can take races that make Psion better, but not races that make Sorcerer better. What's more, Sorcerers benefit more from PRCs than Psions do: psionic prc options are limited, where there is a vast amount of options for Sorcerers, and Psions get class features as they level while Sorcerer is a front loaded class (though this last point is an important component in comparing classes, so I will concede its validity.). Also, when taking 20 levels of a base class you don't NEED skills at all, and its unnecessary this shortcoming of the Sorcerer class in posing the question, especially without pointing out any shortcomings in the Psion. Unless, of course, it was your intention to shape the debate.
Moving along, as I see it, the points in favor of Psion over the Sorcerer are as follows:
1A. They receive a higher power/spell level earlier than Sorcerers.
1B. They can know more high level powers/spells than Sorcerers can.
1C. They have more versatility in how they spend their power points than Sorcerers have in spending their spells/day.
1D. They receive more skill points than Sorcerers in normal play.
1E. They have better skill options than Sorcerers, in particular UPD, Autohypnosis, and Social skills depending on discipline.
1F. They receive bonus feats.
Likewise, as I see it, the advantages a Sorcerer has over a Psion are:
2A. At 1st, 6th, 8th level and higher, they have more 'points' per day than Psions.
2B. There are more arcane spells to choose from than psionic powers.
2C. Their metamagic mechanic is slightly better than Psion's metamagic mechanic.
2D. They do not need to pay to augment their spells.
2E. They have more support in general, for feats, prcs, and itemization.
2F. They have cantrips and a familiar.
Now for a more in-depth look.
1A. They receive a higher power/spell level earlier than Sorcerers.
Psions hold a similiar advantage to Wizard's that make them superior to Spontaneous casting classes; that is, they recieve each new spell level beyond the first one level earlier. Psion was most likely never intended to be compared to Sorcerer, Wilder was supposed to be the Sorcerer's psionic equivalent, while Psion was more likely supposed to be an analogue for Wizards. So the question is how distinct is this advantage? Well, in normal play, you will definitely notice the power shift as characters level, but with a Psion and a Sorcerer the differences are harder to notice than with a Wizard and a Sorcerer. The reason for this is that Psions learn powers from a different pool than Sorcerers, so there is less overlap. With a Wizard and a Sorcerer in the party, the difference is apparent and soul-crushing.
Wizard: "I just got a rocket launcher, and me and the other wizards were having so much fun playing tag, it was awesome!"
Sorcerer: "Ah man, I haven't got mine yet."
A while later...
Sorcerer: "Hey man, I got my rocket launcher, can I play now?"
Wizard: "Oh, I'm already bored of that. Besides I'm getting my nuclear fission reactor next week anyway, so I wont have time for rocket launchers anymore."
Because Psions and Sorcerers don't draw powers/spells from the exact same pool, its harder to compare, you would have to pick out equivalent spells and powers, and this gets into subjective opinion. No matter how you slice it, Energy Ball does not equal Fireball, its just very similar. But generally speaking, knowing a level 9 power is better than knowing a level 8 spell. This gets muddled in standard play, where players will be gaining powers left and right. A Dungeon Crasher Fighter gains his power ups at level 2 and 6, like a Sorcerer, while a rogue gains its extra damage at 1, 3, and 5. A Cleric gets higher spell levels on odd numbers, a ranger gets improved combat style on even numbers. So forth and so on. Their power relative to the party fluctuates, and the advantage that Psions show is not as distinct as it might appear on paper; especially if you don't know whether you are going to fight the boss at level 7 or 8. However, this can be a trap for comparing classes as a whole, especially early on when there are more marked differences in spell levels, such as ECL 3 and 5. A psion might crush a sorcerer at those levels in particular because a sorcerer does not have the versatility base to compensate for the power difference in gaining a new spell level. This is not necessarily a very good judge of strength of classes however; fights at odd levels favor the Psion, fights at even levels favor the Sorcerer... but the fights at even levels do tend to favor the Sorcerer less than the odd levels favor Psion. A higher level power>more spells of the same power level for the most part.
1B. They can know more high level powers/spells than Sorcerers can.
Both Psions know 36 total spells by level 20, Sorcerers know 34. This should be roughly the same, but psions pick their last 3 powers available to them from any power level 9 or below, while sorcerers were forced to spend their 34th on a 2nd level spell a while back, and so have no such freedom. This difference in high level versatility is a clear advantage to Psion, as they have both more high level powers, and more powers known, thus more versatility and more strength.
1C. They have more versatility in how they spend their power points than Sorcerers have in spending their spells/day.
The power point system does have flaws, but the versatility in what spells you can cast can't be ignored. Putting aside augmentation and point differences, using the power point system is better than Versatile Spellcaster and Arcane Manipulation combined. If you wanted to you could break down a 9th level spell into 17 first level spells, or combine 17 first level spells into a 9th level, all on the fly, naturally, with no extra book keeping. This is clearly a point in the favor of psion.
1D. They receive more skill points than Sorcerers in normal play.
Psions are Int based. Sorcerers are charisma based. Psions will already have as much int as possible, giving them more skill points, Sorcerers have to go out of the way to get more skill points, and their cha will only help them with Bluff. A Sorcerer can, however, easily have just as many skill points as a Psion, depending on the ability generation system.
1E. They have better skill options than Sorcerers, in particular UPD, Autohypnosis, and Social skills depending on discipline.
More importantly, Sorcerers don't care about having skill points. Why? Their skills suck. Aside from concentration for casting defensivly, spellcraft and knowledge arcana for when you hit epic, and bluff (admitadly one of the best skills in the game) they have nothing. Shapers have UPD, which, while not being as good as UMD, still can be great. They also have Bluff and Disguise. Egoist has autohypnosis and balance, both situational but godly when they come up. Telepath has all the main social skills. And the other disciplines have good skills as well.
1F. They receive bonus feats.
Enough said.
2A. At 1st, 6th, 8th level and higher, they have more 'points' per day than Psions.
Sorcerers have a lot of spells per day. To be able to compare that to Psions one would have to convert this into point values (and no, I'm not talking about the spell point system here, I'll give my opinion on that elsewhere). This gets a little wonky because presumably Psions recieve extra points to help them augment spells, but just by taking the spells per day a sorcerer has at a given level and converting those into power points, we recieve the following chart
Lvl Sor Psi
1 3 2
2 4 6
3 5 11
4 15 17
5 18 25
6 36 35
7 44 46
8 70 58
9 98 72
10 114 88
11 130 106
12 174 126
13 194 147
14 244 170
15 268 195
16 326 221
17 354 250
18 420 280
19 452 311
20 486 343
From this we see that Sorcerers have more 'points' at levels 1, 6, and every level 8 at beyond, culminating with just over 1.4 times the 'points' of Psion. While Psions can manifest more powers per day than Sorcerers can cast spells by manifesting 343 1st level powers, and can produce more 9th level effects than a Sorcerer, and Sorcerer does have more total 'spell power' at level 20.
2B. There are more arcane spells to choose from than psionic powers.
WotC decided to not to support psionics nearly as much as arcane spellcasting in 3rd edition. Their reasons, good or bad, don't matter; this is the way it went. More support means more spells are in print than powers. More spells being printed means more variety, and more variety means an increased difficulty in maintaining balance, giving more powerful spells a chance to crop up, while psionics sit stagnant. Struggle balancing Sorcerer with Wizard led to a collection of Sorcerer-only spells, some of which are rather strong. Since Psions weren't being supported, their was no effort given to balancing them with Wizards. All in all, this is a point in favor of Sorcerer.
2C. Their metamagic mechanic is slightly better than Psion's metamagic mechanic.
We are not looking at feats or ACFs here, just a raw mechanic of the class. Psions have to expend their focus to use metamagic, Sorcerers have to use a full round action. Regaining your focus takes a full round action that requires a DC 20 concentration check and provokes an attack of opportunity, so if a Psion wants to use a metamagic twice in an encounter, he has spent the equivalent of 3 standard actions and a move action over 3 rounds and potentially provoked an AOO, where a Sorcerer has used 2 move actions and 2 standard actions over the course of 2 rounds. Advantage: Sorcerer.
2D. They do not need to pay to augment their spells.
As I stated earlier, its hard to exactly convert spells into points because you do not need to augment spells. If we included the points that Sorcerers have from 'augmentation' they would have 1080 points at level 20, over three times that of the Psion (not factoring for bonus spells or power points), and Sorcerer would be on top point-wise from level 1. Psions often get bonuses for augmenting their damage spells by gaining increased DCs, but this is not nearly as big of an advantage as one might think, and being limited to manifesting 17 powers at max caster level a day hurts. Again, all of those powers could be 9th level powers due to the versatility of the power point system, but you are still sacrificing versatility and endurance to be able to keep up with the damage out put of a Sorcerer. And at the end of the day, if a sorcerer used all of his spell slots 3rd level or above to cast fireball, and a Psion used all of his power points to throw energy balls, the Sorcerer would put out on average 2940 fire damage, and the Psion would put out 1543.5. And the Sorcerer would still have 1st and 2nd level spells. One point for the Sorcerer.
2E. They have more support in general, for feats, prcs, and itemization.
While the Psion has a few very notable and powerful feats and items, and some decent prcs, Sorcerers have access to the strongest prcs in the game and an enormous variety of feats and items. This goes right back to the whole support issue. In order to sell more copies of books they printed, WotC tried to put things that would interest everyone in each one. This meant that almost every book, and even most adventures, came with stats on magic items, prcs, and/or feats, because they found people were more likely to buy books with character options than pure fluff books. Because spell casting was receiving support and psionics weren't, this means that almost every book printed has at least one spell casting class in it, one item that helps spellcasting, and/or one feat that benefits spellcasters, and odds are it doesn't have anything for a Psion.
2F. They have cantrips and a familiar.
Enough said.
