I liked Muppets Tonight. It was no Muppet Show, but what is? There were plenty of misses among the sketches, but that's true of any show with that sort of format--including TMS.
One thing, though. I've been watching a few eps on YT lately, and I think they were trying too hard to be edgy or something. Like they were trying to prove that the Muppets weren't just for kids, but they forgot how the Muppets achieved that in the first place, and just went for skirting-around-sex jokes and too many "grown up" pop culture references. I like the show, but I don't really let my (small) children watch it. Whereas they can watch as much TMS as their little hearts desire.
But, to keep on topic, I liked most of the MT characters ok. Including Clifford. And Andy and Randy. There! I said it! Don't ban me!
I wasn't a big fan of Johnny Fiama and Sal when the show aired, but I think they're funny now. I wish Kevin Clash and Brian Henson could come back and work with the Muppets once in a while, just for grins.