I know about the official position "Use v7Beta for testing ONLY".
I'm a new sme user and this is just what I don't do. I use sme 7beta5 for a my own business production website and everything is fine. I think (this is my own point of view), it's a chance for newbies to use lastest beta version and try to understand how it works in a real world. If we know where important data are stored and how to restore it's not a problem using an "unstable" release. In an other hand, taking "risk" can help developpers. Only active users can report problems. I'm sure, I learn more on sme doing so and be ready when 7 will be available. I'm just "paranoïac" with backups.