I use it on my iPad all the time because during the day I often have my iPad connected to a 27" monitor, and that extra screen space is nice to have a few windows open.

Using an external KB and trackpad, the iPad generally feels pretty good this way, though Stage Manager does still have quirks, of course. The worst thing being that when you are typing into an input, they put this little language "helper" thing next to the input and it often covers up things you want to see or interact with. It's terrible. They could easily fix this by putting that little thing at the bottom corner of the screen (which is what they do when you bring up Spotlight). Or destroy it altogether.