Cloud crossdressing is fun especially seeing all the different variants things can play out, but it is also pretty short lived in the end. It's the kind of cute and neat details that make this section as memorable as it is, but I wouldn't put it as one of the best side content either.

Sphere Break I like a lot actually, as a big fan of X-2 I've always rather enjoyed it. It mystifies me to this day how this is supposed to be (in-universe at least) a "competitive game" where "either player can win", it really is just challenger vs challenge in practice, but hey, what do I know. Something I don't like about the game though is its lack of longevity. The game is at its most fun when you just have Coin Count Echos and somehow have to beat enemies like Shinra. Once you have Multiplier Echos the game becomes kind of obscenely easy (although you still lose if you make a single mistake) and not very exciting. Still it was fun while it lasted.

But I'll have to go with the Cavern of the Stolen Fayth. It's one of the few truly optional dungeons that X has, and it's honestly kind of refreshing. The upcoming Gagazet section suffers from pacing issues insanely so and having this entirely optional section before it that still feels super rewarding with great loot, an extra aeon, plus kinda really getting you more into the groove of capturing monsters for the Monster Arena, does pretty well at offsetting this issue. Just makes me wish X had this kind of thing a little more often than it does.