I quite like it, I generally like how it looks, and there was less of a learning curve than I expected there to be. Things mostly work without needing you to know HOW they work (though that is fun too). I am sure it will get more active as more people move over, but it's actually the perfect amount of activity for me right now. I can check in and there is usually some new stuff without worrying about things moving so fast that my voice gets lost in the noise.
Big plus is I can be fairly open about my leftist politics, at least around here, and not be downvoted into oblivion. Nor does everything thread even tangentially related to China devolve into racism within five posts.
Are there a couple niche communities I miss? Sure, I might recreate them myself honestly, somebody has to. Otherwise, I don't miss much.
Living in Japan, this almost didn't register to me. I have literally never met anybody that didn't have one. When you move out, you use your family's old one until you can buy a newer one.
Everyone should have one, absolutely.