Why we moved away from AWS
EC2 was designed for elastic computing. On demand high computation (low memory) that are elastic.With that in mind, pure EC2 is a terrible choice for general web application hosting.If using the complete AWS set (S3, simpleDB, etc) then it makes more sense as stuff like db hosting can be pushed out to their services designed for it, but if you're gonna fire up a windows box, stick SQL server on there and use it as a general web app hosting environment then it is a terrible choice.Unfortunately, it's a choice that still appears to be easy for management to justify:
   It doesn't require a server admin to use, it doesn't require mirroring or backups because obviously amazon EBS volumes can't die because they're in the cloud. The extra cost and lower performance is obviously just an Ok side effect of these benefits.(Yes, I'm being sarcastic here, but it's all arguments I've seen made.)