I also find Bluesky's underlying tech interesting. The more i looked into Mastodon the less interesting it felt. I especially didn't like that as a small Mastodon instance i'd struggle to get my updates fed into the larger instances and struggle to get updates as quickly. Instances prioritized updates to/from larger instances.

This was all quite early though and i'm sure i misunderstood things. Just answering the question as i personally perceived Mastodon.

On the non-tech side, i find Bluesky's model for moderation to be really neat. I hope it continues to expand in features/implementations.