I thought that this episode was really creative and a lot of fun. I love it when Fringe mixes different types of media (special effects, animation, etc. combined with the normal footage) so the Monty-Python homage was fantastic to see, and I was very amused by the fairy.
What made this episode stand out was not only the creative factor behind it but also the emotional component of it. The scene where the couple are saying goodbye to Michael came across (to me, at least) as an echo of Peter and Olivia saying goodbye to Etta in 5.04.
The very end of the episode with Walter was also a great emotional moment, calling back to one of Fringe's finest episodes.
I was surprised to find out that Sam Weiss had died, and though I thought it was a great twist initially I was slightly disappointed after because I realized that we won't see him anymore
Anyways, I rated this episode Excellent, for the creative quality of it and the emotional impact. The story was not as deep as others, but it was told in a unique way, which I really liked.