Absolutely, very happy Fastmail customer here! My only qualm is that their apps could be better at multi account (switching is too much of a hassle), but that's the only problem I ever had, and I work around it by using different mail/calendar clients.
If you just have a single account with them though, their app is quite excellent and has everything (mail, calendar, notes), no need to get multiple apps and stuff like DAVx unless you want to.
If you just have a single account with them though, their app is quite excellent and has everything (mail, calendar, notes), no need to get multiple apps and stuff like DAVx unless you want to.