As someone that grew up with the Muppets and loved them just as enthusiastically through adulthood I found the show to be a breath of fresh air. I was laughing out loud within the first few minutes and that's something I haven't done with any 'comedy' show in a very very long time. There's something about seeing all my favorites on the air again that makes me feel like a kid again, but the adult humor (and I mean that in a sort of mild way, because it's not remotely what I would personally consider raunchy) kept it fresh and suited for the adults as well. The more adult humor was there, yes, but as innuendo. In my opinion it's always been there, subtly under the banter only now it's more noticeable for those of us that want to see it. And those instances were scattered.
Was it flawless? No, but it's the Muppets and I for one am more than grateful to ABC for giving them new life because I missed them with all my heart.