I like how easy WebFaction is to use as a developer. They make it easy to set up databases users and email addresses through their web interface without throwing too many options in your face at once, and it's also easy to control stuff through the command line if you're comfortable with that. Lots of good integrations too.

This is where other and myself have difficulty with their services....There isn't a great way to know what size server package you need for websites. I started with the basic package and had numerous problems with the sites going down. The fact is...my server choice was too low for what I needed. It is no different than having a computer with 1 GB of RAM and it sucking. If you need any kind of performance, you need to start with a minimum of 4 GB of RAM (currently the $30 package) and it will run 10 Rails Applications easy. Stop being cheap and thinking you deserve better!! Now the best thing about Webfaction is emails. I have had little to no problem with email accounts working and not having to pay $5 per email is a HUGE cost savings for reliable email accounts. I host 33 Rails websites for $60 including over 100 emails accounts and there is no where more reliable than Webfaction.