Kevin James strikes me as a small doses (not LITERALLY, of course) kinda guy, hence why he worked out so well in Hitch.  He wasn't in it non-stop, so whenever he was, the parts were enjoyable.  That's why he works on a sitcom, smaller doses.  I don't think I can take his comedy routine for an entire movie.  I haven't found a fat man consistently funny since John Candy, and most of his comedy DIDN'T center around his weight.