I still find the whole "head shape" complaint in regards to both he and Steve to be a tad ridiculous. Yes, the way Jim shaped Kermit's head with his hand played a factor, but we also have to keep in mind something: no two puppets of the same character are ever going to be 100% exactly the same - we may prefer the certain appearance of a specific puppet over others, but they can never be exact clones of another as we wish . . . I hate the shape of Big Bird's head right now, it has way too many feathers, making his head look way too gianormous, but I just have to suck it up and accept this is what the current Big Bird puppet looks like.
In regards to Matt's performance as Kermit, I think he has gotten better at capturing Kermit's inflections and mannerisms, but the voice still sounds too much like a Matt Vogel voice (though not quite Constantine) than it does a Kermit voice, to me.