The DM was a bit unhappy about it, because who refuses to fight with a sword that is a personal gift from the god of fighting evil things, especially when you are in the business of fighting evil things? I suspect that he actually think that the sword is the coolest thing ever, and even that he may not understand why I don't like Burst enchantments like he does.
I happen to be writing the definitive work on Weapon Abilities right now and I increasingly hate Burst.
Here. Show this to your DM
I am a paladin with a Str of 14. I have a +1 Longsword with Shocking burst.
Lets say, to make the math simple, On average I hit 50% of the time.
Damage
7.5 (1d8+3 base) * .4 (hit on 11-18) = 3.75 avg damage
3.5 (1d6 Shocking) * .5 (hit on a 11-20) = 1.75 avg damage
5.5 (1d10 on a critical) * .1 (crit on a 19-20) * .5 (confirm on a 11-20) = 0.275 avg damage
7.5 (1d8+3 base) * .1 (Crit on 19-20) * .5 (confirm on a 11-20) *2 (Crit Mult)= 0.75 avg damage
Total: 6.525 avg damage
Now... Let's drop the Burst and just take a good old fashioned +1 so our new weapon is a +2 shocking longsword being wielded by the same guy.
8.5 (1d8+4 base) * .45 (hit on 10-18) = 3.825 avg damage
3.5 (1d6 Shocking) * .55 (hit on a 10-20) = 1.925 avg damage
8.5 (1d8+4 base) * .1 (Crit on 19-20) * .55 (confirm on a 10-20) *2 (Crit Mult)= 0.935 avg damage
Total: 6.685 avg damage
Now, Let's try it even further... +3 Longsword
9.5 (1d8+5 base) * .5 (hit on 9-18) = 4.75 avg damage
9.5 (1d8+5 base) * .1 (Crit on 19-20) * .6 (confirm on a 9-20) *2 (Crit Mult)= 1.14 avg damage
Total: 5.415 avg damage
Now, let us assume our enemy doesn't spend 18,000 gp for shock resistance which TOTALLY negates the energy damage. And lets assume he doesn't have a friend who can buff him with energy resistance, because if you are wielding a weapon of your God, there is NO CHANCE that nobody else will have heard about that sword and how it does shocking burst. Nope. NOT A CHANCE. But lets ignore that...
The burst weapon sucks. It sucks my left nut.
The shocking weapon appears to be a good investment. Or does it? Le's up that Paladin's Str by 4 and give him an 18, shall we?
+3 longsword w/18 str
11.5 (1d8+6 base) * .6 (hit on 7-18) = 6.9 avg damage
11.5 (1d8+6 base) * .1 (Crit on 19-20) * .7 (confirm on a 9-20) *2 (Crit Mult)= 1.61 avg damage
Total: 8.51 avg
+2 Shocking longsword w/18 str
10.5 (1d8+5 base) * .55 (hit on 8-18) = 5.775 avg damage
3.5 (1d6 Shocking) * .65 (hit on a 8-20) = 2.275 avg damage
10.5 (1d8+5 base) * .1 (Crit on 19-20) * .65 (confirm on a 10-20) *2 (Crit Mult)= 1.365 avg damage
Total: 9.415
Original Difference: 1.27
W/18 str difference: .905
As your base damage goes up, the return of the humble +1 enhancement catches up with the +1d6 electrical damage, that does not scale with increased base damage. (But does get you some return with increased to hit.)
I'll save you the math, but basically, at around a Str of 28, a +1 to your sword is better then +1d6 elemental damage. This doesn't factor in a whole bunch of crap, like power attack, buffs by the rest of the party, yada yada yada.
And remember:
A critical hit means that you roll your damage more than once, with all your usual bonuses, and add the rolls together. Unless otherwise specified, the threat range for a critical hit on an attack roll is 20, and the multiplier is ×2.
Exception: Extra damage dice over and above a weapon’s normal damage is not multiplied when you score a critical hit.
My Point is, the energy damage is worth it for weak characters. Strong melee types are better with damage that adds to your base weapon, then the damage is multiplied by your critical.
Burst Just sucks. It Just Sucks. It always sucks. It will always suck.