I can't really give you a blanket recommendation, it really depends on your use-case and your familiarity with mysql. If you do not need replication and you can schedule the daily backups at a convenient time, then RDS is a good option. I wouldn't want to run mysql without replication for any app that is business critical. Also, we tend to run 24x7 stuff where the impact of EBS snapshot backups is often painful. Plus with the RightScale mysql Server Templates the replication setup is easy and has so many advantages. But, of course, I'm biased ;-) The best I can recommend is to give the alternatives a spin.