Most startling part of the episode for me was the realization that Chong's 72 years old. Good gravy!
There was a lot to love about the first segment. The cheesy intro to the "That's Kent-ertainment" segment, the Cheech & Chong origin story, the return of the really, really tall guy, and Homer wanting to meet Don Johnson.
Unfortunately, it just couldn't bring the funny for the rest of the episode. I couldn't get into the B-plot with the crazy cat lady or the main plot with Cheech and Chong making dueling comedy duos. And the Shakespeare ending was just plain random.
Homer: Chong is refusing to fall back on his old catchphrases! Bart: Aye caramba!
I can't get over the fact that they named the guy with fire powers FLINT. That's brain-smashingly stupid. The retconning was bad...REALLY bad...but the worst part is the the story didn't benefit at all from the changes.