Cyan, I'm as opinionated as they come. Shoot fast and from the hip, my friend.
To answer your question, it's the little things, the subtle differences. And I confess, I'm actually planning to replace arcane and divine magic with psionics. And call the psionics magic.
For a particular setting I'm writing up, anyway.
Yes, there are powers in UP that seem almost as wonky as spells in D&D. But overall, as a whole, I'm finding they just work for me better than Vancian spell slots. Starting with the power point system; a psionic can pump power points into an ability until his PP well runs dry. He can use any power he knows whenever he wants if he has the points available. There are practically no components, other than the occasional material component, it all comes from the user's brain.
Then there are the powers themselves. Telepathic powers are very prominent, which works with my favored concept of magic. And I just prefer how they're written to D&D spell write-ups. Again, it's the subtle things. I'm still reading through the thing, so maybe I'll have more concrete thoughts on the subject afterward. A big thematic difference for me between magic and psionics is that magic often seems to depend heavily on some kind of external intellect to power the effects, while psionics does not. A lot of spells are fire-and-forget, while fewer psionic powers are. E.g., animate object seems to rely on some kind of conjured intelligence to power the animated object. (Never mind that there's a similar power in UP, I'm trying to make a point here
; Edit: also, concentration in 5e does seem like a big step in my favored psionic-y direction)
.they seem to be one-trick ponies. You hear about mediums, not "mediums who also blow crap up, fly, augment body parts and go nuts at the prom covered in pig blood."
Jedi display telekinesis, precognition and sixth sense, telepathy, mind trick, super-jump, super-speed, lightning projection, energy absorption and reflection, hyper-accuracy and skill boosting, speak with dead/living (edit: forgot blindsight)...and that's just off the top of my head from the films, I'm sure there's more in the wider Star Wars Universe. With a suite that broad you can shoehorn in pretty much anything and feel consistent about it.
Most of the UP classes seem to be written the way you mention though, and I'd like to eventually reflect that, but I also want to have versatile spellcasting classes.
Yes, it's just magic re-fluffed (and re-crunched, IMO), but that's the part that works for me. Psionic-y magic works for me, hand-wavy chanty magic, not so much. Then there's the familiarity factor. Magic has worked the way it has in D&D since I first played it as a teenager. It's very familiar. Psionic-y magic has a fresh, new, mysterious feel to it.
