Well...you do have 5th level casting ability, but you're no longer as good at being a rogue or a sor/wiz as you would have been otherwise, and especially in the case of spellcasting classes, having lower progression can really hinder a character. So that's why I figured it wouldn't be a bad thing anyway. Besides, you are losing things with this prc...skill points, possibly some class skills (which i haven't checked for, though), many cool rogue abilities, medium bab, wizard bonus feats, familiar progression (people say this doesn't mean much, but familiars can be really really helpful when used well), and you need to take the prerequisites which you may or may not have taken to begin with, all to gain just a little extra sneak attack damage and the ability to pick pockets at a distance.
Personally, I don't think it's a very imbalancing thing to give them the extra +2d6 sneak attack...but like I said I wasn't aware of any errata, but apparently since there is then oh well.
Personally, I don't think it's a very imbalancing thing to give them the extra +2d6 sneak attack...but like I said I wasn't aware of any errata, but apparently since there is then oh well.