If you guys can bring up examples, that would be helpful to the rest of us...
The account I bought initially had 15 MB space limit (it was a 15$ one time purchase for life membership). They never increased this limit... The web interface didn't auto refresh, unless you used "poll" which then only refreshed every 30 minutes.
When I did switch there was a bug in the forwarding that resulted in some of my emails not forwarding (although this went away and only happened to 3 emails).
They might have had better improvements for accounts that required continuous payment, but certainly not mine. It obviously got surpassed by free alternatives.
Despite this criticism, I am very satisfied with fastmail, they served me well for a long time.
I've observed the opposite. They constantly make improvements to their service.
They've got boatloads of features and they're getting better all the time.