Boy, this is a really funny, well-performed sketch. I would put this one right up there with the best sketches of the classic, pre-1990 era.
Perhaps more than any other Bert & Ernie sketch that I can think of at the moment, this one has jokes designed to go over kids' heads, and I love that.
I'm not entirely sure who's performing Bert here. I'm 95% sure it's Eric Jacobson rather than Frank Oz, but I'm not absolutely certain. The one and only thing about Jim Henson's death that's slightly advantageous is that if you know when the sketch was made, you can be sure of who's performing his characters (or at least you can look it up).
Conversely, the one and only disadvantageous (if that's a word) thing about Eric Jacobson stepping so successfully into Frank Oz's performing shoes is that sometimes it makes it hard to give credit where it's due