hmm never heard of session, it looks like it's a fork of Signal.
Discussion
We use Session for the Damus Translations 30-person group chat and it works pretty well. It forked from Signal several years ago and seems to go a step further from Signal to harden privacy.
They sure begin to receive more attention from the Nostr space. Perhaps they attract some talent to upgrade the Mac and iPad experience that way, Signal certainly outmatch them in that area.
We use it as our business chat and it works as a charm.