The main reason I hate ultra smurfs is because:
a) they get all kinds of special characters-some of which I believe are pointless I mean telion and chronus, were they really necessary)
b) GW like to put emphasis on the smurfs which is fine. Until we either get the point where fluff is changed so it sounds more dramatic or features the ever sooooo boring story about the few brave souls holding back the masses. Why can't they come in, kick ass and then move on?
c) They had a stupid colour scheme although the gold trim appears to fix this now.
d) GW always find ways to "force" the smurfs on new players. I know space mainres sell best for GW but let the little kids decide whether they like the other chapter (or even races) first!!
Rant over. I think it would be cool to field a unit of special character (although maybe this will only be possible in larger games)