I've been using their cheapest tier for a couple of months and have no complaints. Seems plenty fast, haven't had any downtime. Super easy to create/delete/reboot "droplets," add/remove/modify DNS, etc. They have some neat looking snapshot/backup features that I haven't really investigated.
The one thing that's kinda weird is that their web interface don't seem to give any sort of indication of how much of your allotted bandwidth you're using. Maybe it's buried in a menu somewhere and I just haven't found it. In any case, I just installed vnstat to monitor it myself.
On the whole, I'm quite happy with it for my (admittedly extremely basic) needs.