We've recently started playing a campaign based on a challenge from our DM, who was interested in an all arcane caster game. The challenge was basically to play with a highly unbalanced party, in which no one could play a melee combat oriented character, nor could anyone play a divine magic based character. Everyone had to be a "primary caster" focused on dealing damage.
We've got two psions, a sorceror, and (yours truly) a wizard based arcane trickster.
I think it will be an interesting campaign to test out the different sides of the argument of this thread, though it may be a year before we've reached a firm conclusion.
At this point, I expect to find that psions and sorcerors simply have different strengths. Focusing on the strengths of the psions and paying little attention to their weaknesses will give an inflated impression of their power on paper.
Theory: I think mages are more efficient than psions, but that psions can do better burst damage.
Let's compare some spells to powers.
Comparison 1
Spell: Orb of Acid -- ranged touch for 1d8 damage + 1d8 per 2 levels, max 5d8; no save, no SR. [Bread and butter for an Arcane Trickster as you can sneak attack with it, which is neither here nor there for most....]
Power: Energy Touch -- ranged touch for 1d6+1 fire or cold damage (or slightly different electric or sonic damage); no save, but SR applies. For every additional power point, add another d6+1 damage.
Comparison: 1d8=1d6+1 on average, so at level 1 damage is equivalent. As the level rises, the psion will need to spend more power to keep up with the damage, so that at level 9 the psion will need to expend 5 power points (the equivalent of a 3rd level spell) to do what I can do with a first. The psion has a significant flexibility advantage, but not needing to worry about SR isn't shabby.
Comparison 2
Spell: Fireball -- d6 per level fire damage up to 10d6 in a 20' radius burst. [Bread and butter for arcane casters everywhere.]
Power: Energy Missiles -- 3d6+3 fire or cold damage +1d6+1 per additional power point, which also increases the save DC by 1. Less damage if used with electricity or sonic.
Comparison: Energy missile is available earlier to Kinetisists, but is so nice that many other psions will spend a feat to get it at about 6th level. At 5th level, the wizard does 5d6 fire damage. At 5th level, a psion does 5d6+5 fire or cold damage for an equivalent cost, and has a save dc 1 higher than the equivalent mage. At 10th level, the mage does 10d6 damage, and for an equivalent cost the psion is still doing the same 5d6+5. If he's feels the need, however, the psion can (for the equivalent cost of more than a 5th level spell) deal 10d6+10 damage and gain a whopping 6 point higher save DC than the mage's fireball. The saving throw bonus is the psions most impressive advantage here.
The targets effected are different, of course, and with tightly packed opponents the mage will effect more than the psion. Usually, in my experience, enemies will spread out, minimizing this advantage. The psion can also use energy missiles without fear of bringing down "friendly fire" on an ally in melee range of his targets, and gains a tremendous benefit against creatures with evasion in that he can switch the saving throw type to fortitude and negate that ability. The ability to choose which energy type to use on the fly is also a fantastic benefit.
Overall, this comparison is highly in favor of the psion. Note, however, that unless the psion happens to be a kinetisist, this power cost a feat. At the risk of complicating the comparison, let's assume the mage spent the feat on empower spell. At 10th level, an empowered fireball does 10d6*1.5 damage, comparing favorably to the psions 10d6+10, and is still less expensive to cast than the psions augmented power.
Comparison 3
Meteor Swarm: 24d6 area fire damage, plus up to 8d6 impact damage. Primary target can be deprived of saving throw if ranged touch attacks are succesfull. SR applies, and fire resistance applies at 4x the normal amount. Spheres can be dispersed, which might be helpfull if you are fighting some huge horde of weak enemies.
Tornado Blast: 17d6 area damage, plus up to 8d6 impact damage. Neither SR nor fire resistance applies. Opponents get thrown about.
Comparison: Tornado blast has some nice advantages, especially against fire resistant or power resistant enemies. It does, however, suffer a bit in terms of pure damage output, and depriving your opponent of a saving throw can potentially be a big plus for meteor swarm. Note that while Tornado Blast can be augmented, it's capped at the same damage as meteor swarm, and the psion needs caster level 24 in order to get there. Should those conditions be met, the psion also gains +3 to his DC, but at the equivalent cost of casting a 13th level spell.
