Digital Archon said:
I like magic, but i'm also interested in psionics for a possible Eberron game. how do these compare in terms of relative overall power?
Psionics are more powerful overall. They also break some of the conventions set in the core rules.
Both have strengths and weaknesses and magic is better for some stuff, while psionics are better for other stuff, but there are some rather big issues with the rules (IMHO the biggest one is the Psion class being based on the Wizard class despite being a spontaneous manifester class and not a prepared casting class, which is pretty sad, since that's the most basic psionic class and the foundation for the whole system).
Is one way more obviously powerful than the other?
Yeah, psionics are more powerful in general, mostly because of a lot of perks, which basically come for free, though it does depend a little on the way you play. With certain playing styles, the differences will probably not surface much. Psionics, even more than any of the core concepts, require you to adapt a certain style of playing to even remotely balance them with the core rules.
It also depends on the level, though, at low levels the differences are minor and probably neglectable (apart from a few broken feats and powers, but there are broken spells as well), but at higher levels they are pretty large.
They are not 'completely horribly broken'

, but there are a lot of balance issues with psionics and the creator(s) have obviously not quite realized (or don't care about) the full extend of the changes done to the magic system in the 3.0 -> 3.5 transition, as some of the psionic rules are based on 3.0 concepts still.
There are also even more ambiguous and badly written rules in the book than in most other WotC rulebooks (and the extremely lacking errata also only covers a fraction of even the most OBVIOUS errors in the book (and not even the worst ones of those)). Some guesswork is required there. But beyond the core rules, the amount of playtesting done seems to be vastly lower in general. Well, can't blame them for that, really, it takes a lot of time and effort (and thus money) to decently test a complex ruleset like that and even the core rules still had issues afterwards.
A good 'test' to see how psionics would fit into your game is to think about how different (powerwise) the Sorcerer and the Wizard class are in your games. If the Sorcerer is significantly lower in overall power than the Wizard, then psionics will probably integrate well enough. If the Sorcerer is about equal to the Wizard, however, then psionics will break the balance in your game most likely.
Are psionics too horrifically stupid to even bother with?
Stupid? No.
One 'problem' (and a big advantage from the fluffy side) is, that they work VERY different (altho they look pretty equal on first glance, there are huge mechanical differences and many new names and terms). If the extra work of basically having to go through a complex set of completely new rules does not bother you, that's not an issue, though.
I would have to buy the XPH, so i'm wondering if i should bother.
Not really, most of the content is available in the
Psionics SRD.
I understand that we're comparing apples and oranges in some ways, but when you think about it, apples and oranges are both round, sweet and fruit, and as such, have many similarities.
Yup, there are many similarities and many differences as well, but they are surely comparable.
Bye
Thanee