RigaMortus2 said:
A psion could use all their power points on a high level power, where as the wizard could only use theirs a couple of times per day, then they would be stuck with lower level ones. More often though, it is the higher level powers/spells that do the most damage.
This is only part of the Nova equation.
Psions also get the equivalent of certain feats with certain powers. For example, Energy Missile gains:
1) Multiple Energy Substitution feats for free.
2) Equivalent of Shape Spell feat for free.
3) Additional damage per die for free.
4) No damage cap (which is basically what you stated with your level comment).
The only thing that offsets this at all is the extra PP required to boost powers. However, that is not a Nova issue. That is a balance issue. Nova-wise, the Psion can flat out outboost the Wizard.
A 10th level Wizard does 35 average points of damage with a Fireball. He can Empower Spell it to 52 points. A 10th level Psion can do an average of 45 points of damage with an Energy Missile. He can Empower it to 54 average points of damage. He can Overchannel Empower it to 67 average points of damage.
The Wizard is limited to 2 of the Empowered Fireballs and about 4 normal Fireballs or 244 total points of damage. The Psion can do about 8 of the Overchanneled Empowered EMs for about 536 total points of damage (or 11 non-overchanneled ones for 594 damage).
And, the save DC for the Psion is 2 (3 for Overchanneled) higher for EM than for the Wizard's Fireball.
Granted, the Wizard still has spells left over, but the point is, for massive damage in the shortest amount of time, Psions are better at Nova.
Finally, the difference here gets greater the higher the level of the character. The 11th level Wizard is still doing the same damage with these same spells and jumping up to Cone of Cold does not significantly help (since it cannot be Empowered yet) whereas the 11th level Psion is doing ~4.5 (or ~7 for Empowered) more damage for the additional PP.