I’ve been playing around with AWS recently as you can trial it for a year. It’s a really good setup actually and you get great Linux performance for a very small foot print. E.g. On EC2 the tiny free tier 1-core CPU, 1gb RAM, SDD Linux VM on AWS is easily 2-3x faster at loading a WordPress site than a 8-core, 8gb RAM, SSD Linux VM on VMware or Hyper-V. Not quite sure how so I’ll put it down to Magic.
I did dabble with their RDS system for my MySQL database but then I noticed if I used it along with the EC2 instance I had running as a web server, after a couple of days I noticed they were billing for data transfer between two separate Amazon services. On a small wordpress site I’m seeing no performance benefit of being on RDS so I would just run a DB locally on the EC2 instance.