I've been very happy with Digital Ocean for the past half year or so.
I received a free $25 credit for DigitalOcean which I used to test their services, and I personally wasn't happy with their performance. The I/O was horrible for what was SSD. I ran a droplet with ONLY TeamSpeak3 running and would often enough encounter stutter due to latency issues with a even a small group of 3-4 people. They may have improved since I discontinued their services (3 months ago). In any case, I was only using it on a trial basis. With my impression of it however, I'd say it would be fine for a developer looking for an alternative to Heroku/GoogleAppEngine/AWS/etc, but I wouldn't use it for anything which was meant for production use.
Fair enough, I have only used it for development and personal projects.