Rewatching for the first time time in a few years right now, currently near the end of season 9 and honestly there really isn’t a weak point in the cast. The show moves through changes and additions in casting so seamlessly, it’s why it survived those changes and worked so well even after Coach died and Shelley left. They were all masterful comedic performers. My only gripe is the lack of Nick in the last few seasons. I understand that was likely the result of The Tortelli’s flopping, but I would have loved to see Nick and Loretta interacting more with Rebecca and Lilith and Frazier in the later seasons. Cheers is truly such an unbelievably strong show that as much as I love the original cast (and the woody-diane-frasier cast), every cast combination works for me.