I could write my review from scratch, but it's easier to just argue with everything SorO said.
Level 20 feels like level 1 in all but the Class mechanic.
It does seem like they didn't fill out the levels. I like the way 3E and, to a greater extent, Pathfinder, grant new, interesting abilities every 1-3 levels to most classes. It's possible that they just haven't written this part yet. On the other hand, I think one of the major flaws of every other edition of D&D is that a high-level character so vastly outpowers a low-level character. In my opinion, it should be very dificult for a party of level 5 characters to take on a level 15 opponent, but possible. In 3E, it's just not possible.
C. You start with four Skills and at 7th, 12th, and 17th level you obtain a new skill or upgrade the die (d6->d8->d10->d12).
I don't like the new skill system. Two characters with the same class and ability scores have the exact same skill modifiers. Rogue A will pretty much always look exactly like Rogue B. Even the character who's best at a skill is only marginally better than the character who's the worst at it. I know 3E skills are often criticized, but I think it's one of the best concepts in the system. It really allows you to make your character unique.
D. Anything over a +1 Armor/Weapon is a unique item.
This is something I really appreciate. It's not just weapons and armor -- every item is unique. There are no magic item shops, and there are very few simple items which just grant a bonus to something. 3E is all about maxing out your bonuses -- buying the most boring items you can afford so your character will be that much more powerful. 5E makes magic items interesting again.
H. Caster Level doesn't exist.
In some ways, I don't like this, but it's a nice simplification, and makes low-level play easier. If the spell always has a duration of 1 minute, no matter what your level, it's always equally useful. High level caster still get better spells, so caster level still exists to that extent.
K. Save system rewritten to use all six ability scores, good luck there.
I like this. In 3E, it's too easy to have no weaknesses. I like every character to have some weakness.
Because if you want to see +3 Armor, you're going to have to spend $30 bucks on Complete Ripoff.
That seems overly cynical. If a DM wants +3 armor in his game, he can just add it to the game. Sure, Complete Ripoff has been WotC's and TSR's primary money-making strategy since the 2E options books, but the lack of +3 armor is not what's going to sell those books.
3rd's Skill suffer from too many so it's hard to do even trivial stuff? 4th, everyone gets bonuses in everything as they level.
5th's answer: Everyone sucks, all the frigging time.
Some of your complaints, like this one, don't take into account that these are two seperate games. You're not going to play in a campaign that has both 3E characters and 5E characters. 5E is a lower-power, weaker-magic-item game. That doesn't make it a
bad game, just a different one.
3rd had Cleric Domains which gave more Spell Choice and additional benefits. 4th had more At-Will powers.
5th's answer: You get one Domain, but it's less of a Domain and more like a Daily power.
In other words, 3E and 5E are different. This doesn't seem like a real complaint. You happen to like the 3E domains, but they don't really exist in 5E, so I guess that's fine.
I'm not sure what to think about the advantage/disadvantage system. It might play well, but it feels like an oversimplification. Optimizers are just going to figure out how to always give their characters advantage, and always give opponents disadvantage. Then they've won the game. While it's harder to keep track of and can slow down combat, I think I prefer 3E's system of scalling numerical bonuses.
