I love it in principle. I actually dove in and purchased it since I've wanted for so long an email client built around people.

I have a few criticism after actually using it (admittedly for only a few minutes here):

* The lack of an "Inbox" is disconcerting. It actually really is important to me to just see a list of emails in my inbox, most recent on top, with unread messages marked as such.

* People centric is great, but conversation centric is equally important. Apple Mail and Gmail get high marks on organizing emails by conversation thread, but both I found lacking in their organization by person. This app has the opposite problem: It's great for viewing emails by person, but that's like the ONLY feature. I really strongly dislike how it munges together different conversation threads under a person, which at the same time excludes other emails from other people that were part of that thread.

Maybe they'll add these features later but for now I'll probably slink back to Apple Mail and maybe keep an eye on it.

YMMV