I confirm all this. Elastic Beanstalk is so good, I don't even touch EC2 anymore. All my webapps are now being deployed through it. It costs more due to fact that each environment needs its own load-balancer even if only one server is involved which is extra $18/month but it is still worth.

If you deploy code that crashes webapp, just revert back to previous version. Problem fixed in a minute on all your servers.

And you don't even need to do that actually, spin new environment with new set of servers. Upload new version to new environment, do the testing, then promote this environment to production status (takes a few seconds), and terminate previous production environment.

Perhaps other companies can offer service like this too, but my platform of choice is ASP.NET which narrows the field quite a bit.