About xiii mechanics vs new mechanics, I think the DC/HD system is a stroke of genius because it curbs OP combos while allowing them to be in the game. It's the best of every world really.
On the EX charas: how many of the old characters had EX moves that did the same damage as an DM? EX Iori and Kyo have DPs that hit for close to 220. to me, that is op, because of execution. dead fast, really strong.
The idea of an UM 13 is nice. but I wonder how much it would cost them to do that. I mean, we'd want whole teams right? if you put up a poll, I'm sure ppl would want at least 4 new teams (new faces, orochi, billy's team, ???) and that's a lot of animation. I am glad that the EX characters aren't just head swaps though.