I've looked at Notion a few times, and it looks really impressive. It also looks really overwhelming – almost too many features/capabilities, so it's hard to know how it would fit into what I currently do, or what tools I should replace with it.
But maybe that means I'm not the right customer for it :)
A few months later, I'm still using it in place of most other tools that I had been using, with the exception that for lack of an API or good way of pulling the very rich content out, I still use Google Keep for very plain text notes.
But maybe that means I'm not the right customer for it :)