I recently started using Fastmail for a new project I'm working on. The web app might be the snappiest I've ever used. Way better than Gmail. Protonmail is painfully slow in comparison. I'm seriously considering switching everything to Fastmail, but there's always a ton a FUD about surveillance when comparing them to Protonmail. But there's always a lot of FUD thrown at Prontonmail, too. Hard to know how much is true.