I have more mixed feelings than most fans about the Q character, which often led to coasting by the writers and producers. "Yeah, we've got this totally over-the-top character which dominates every scene he's in - maybe we don't actually have to create an interesting story!" Both of the other Star Trek Q episodes that ran this season - "Q Less" (DS9) and "True Q" (TNG) - fall victim to that problem.
"Tapestry" certainly does not. There's plenty of the great Q-Picard chemistry, but without the pitfalls - less overacting by John DeLancie, less of the ponderous speeches that writers gave Picard in his presence.
Besides the fun of sending Picard to revisit his youth (and it is a lot of fun) with Q in tow, we get a thoughtful story about how each little choice matters. The scenes with Picard as a junior science officer really are heartbreaking.
Aside from "Chain of Command", the best of the 6th season.