I usually build centurion only on casts. Casts aren't interested in the 25% tp reduction and 7 (?) to all resistances is pretty mediocre. That's like, probably 2% resistance to that element more? Which is marginal because for the elements that really matter (Megid and Grants.. and maybe Shock) you're basically gambling chance to die or chance to not die with Grants and Megid. Megid especially, since it's an insta-kill. Casts don't have a need for the tp reduction, while the 20 ata is nice, it can easily be made up with a dex mag build (which most HUcasts run anyways which is what I'm mostly referring to). If you look at Centurion Ability, you can't argue that the base stats are better. 30 to all and gives you 3 ata as a bonus, which is nice. I guess it all depends on how much you value the extra resistances and the ata if you're not going a Dex mag build. I always used Centurion Ability over Adept for HUcasts and sometimes RAcasts specifically just because the bonuses that you can't get on Adept are mostly useful to only Humans and Newmans. But, like I said, it's mostly how much you value the resistances and the 20 ata. TP reduction on a cast doesn't matter at all (which if you haven't been paying attention my argument is strictly for casts) and the resistances (to me) are marginal benefits.