I first tried Stage Manager when it came out but quickly gave up on it because of various reasons; a big one was performance of it on my Intel MacBook Pro.
A while back I decided to give it another go.
In general I like how it gives me another layer of organization below each Space (or what the fuck the singular of Spaces is).
What I don’t like is the lack of API’s, Shortcuts, Keyboard shortcuts etc to manage each Stage. And the “recently used” thingy is beyond buggy on wide monitors.