Hi @digitalb.
I can’t comment on the reliability of Amazon’s EC2 servers yet but I have been playing around with them for a week or two now (just for the fun of it) and all good so far 
I wrote a blog post explaining the process of installing the Distro on a local virtual machine and how to then convert it into an EC2 instance. This way you don’t have to use the AMI you mentioned - you can rather build your own one from the latest Distro