I'm sure that the story has been told here before, but what I learned from Jerry Juhl back in '04 was that when they brought Eric in to audition for Piggy, he asked "Which Piggy do you want? First season, second, third? Muppet Movie Piggy?.." etc. The "auditioners" replied, "We didn't know there was a difference."
So he proceeded to nail each version for them.
Now, I gotta respect that. But for some reason, I don't believe that he's been "nailing" Fozzie like I suspect he can. Being a Fozzie fan, I can tell you the differences over the years in Fozzie' voice. And probably the least appealing is the "overblown moron" Fozzie that he's been portrayed as in the last few films. Its a complete hold-over from is appearance as Squire Trelawney in Muppet Treasure Island.. and it's VERY uncomplimentary to a character that, in reality, is quite astute. He's not stupid... no more than any of the other Muppets in their sliding scale of intellect and innocence. They've been playing him as a complete brainless fool.
Now, I don't know if Eric has anything to do with that ultimately. He may be just performing the character as he's been told. I know that when the Palisades Muppet figures were being made, Palisades wanted to do a "First season Fozzie" figure, but JHC Marketing put a kibosh on it for one reason or another. Evidently they just wanted the "NEW" Fozzie to be represented.
So it may be that there's a deliberate "dumbing down" of Fozzie. Who knows? Once the character moved beyond the control of Frank, he was subject to the whims of whoever was at the director's chair.
And I certainly don't think Eric is doing justice to Animal.
So, on the whole, I'd have to put in my vote for Frank. Both then and now.
-Gordon