I just received my invite code today and took a quick look around the app. Like Mastodon I do not prefer microblogging platforms. And that's all I know about Bluesky.
It's just Twitter run by the old CEO. There's some promises that it's going to be decentralized at some point, but no real motion towards that yet AFAIK. Anyone on the Fediverse should just pick Firefish or Mastodon over it.