Email search is poor. It's not important enough to me to switch, but it's almost surprising when a search returns the emails I'm looking for.

Calendar is too separate from email, especially in the apps. I can't accept invites from other services, or if I do, they don't show up in Calendar. I forget, because I gave up on using it within days.

Pass is terrific, so far. Transition to it was easy- much better than some commercial offerings that have been around a lot longer. Password generation options are top notch.