Combat-heavy probably means many combats per day, which is a good start to keep psionics in check (since psionics are not balanced, they have to be kept in check
).
Tyrion said:
Are the psionic classes balanced and interesting?
There are quite some balance issues with magic in the core rules already. Psionics are similar, just worse as they deviate from the mean even further. It's fairly easy to make unbalanced psionic characters, which does not necessarily mean, that they are completely overpowered... in particular, they will probably be uber effective in some combats and then not so much afterwards (which by itself is pretty unbalanced).
Interesting is a matter of personal preferance. To me... no, they are not particulary interesting. Psions are way too similar to Wizards and Sorcerers, just with worse mechanics (from a balance point of view). There is no need for them. Others like their flavor. Others especially like the mechanics. As I said, it's a matter of personal preferance, whether they are considered interesting or not.
If you and your group, and those are the only people that really count, think they might be interesting, then it's certainly worth checking out. But be warned, you need to
thoroughly read and understand the rules, before you can use them reasonably well. They are quite different to the core magic rules, altho similar in many areas.
Are they outshined by wizards or clerics?
Certainly not. Psions are the top rank of the most powerful classes, at least the same level as Clerics and Druids.
In a three or four person party, is it good option to substitute a psionic class for one of the more "core" classes?
As a 'substitute', the psionic classes can certainly be used in similar roles as many of the core classes. The Psion and Wilder are similar to the Wizard or the Sorcerer in that way, and the Psychic Warrior (and to a degree the Soulknife) is closest to the Fighter (altho, a bit different). I think there is also a psionic healer class in Complete Psionics (Ardent?), and a psionic rogue (Lurker), and some other psionic classes. There is also a psionic rogue (kinda like the Psychic Warrior, just replacing fighter-stuff with rogue-stuff) on the Wizard's website.
One thing where psionic characters are rather bad is buffing the party. That's one of their big weaknesses in a party environment.
Bye
Thanee