I've had a leg in both Twitter and Mastodon for years now and post simultaneously in both. I prefer Mastodon in basically every way. The main thing that keeps me on Twitter are folks who aren't (yet) on Mastodon.
@kyle Ditto except I'm on Friendica so I can federate to Diaspora too. I will say that in terms of UX Mastodon is probably better. The UI is more responsive. The backend is probably more responsive too. I do prefer a more Facebook-like timeline view which Friendica gives me as well. The wonders of the fediverse is that you probably wouldn't know I'm on a different network.