I've always kind of felt like the specialized kits were either a tool to enforce role playing or a crutch for people who didn't like role playing part as much as they like the dice rolling and loot gathering. It is up to the DM to set which tone will be used. I mean, I totally see the benefit in using a "Red Wizard of Thay" kit in an adventure that is responsive to that, i.e. it's either about Thay, the mechanisms of Thay, or gives the PC a positive or negative reaction etc for being a Red Wizard. But, what I would hate to see is a player take it and instead of role playing, be all "Red Wizard, Red Wizard". Like I said, I never played with kits, so I can't say for certain, but it seems like a bunch of extra crap.
