I've been working with 7.1 for a few months now, and decided to finally convert over.
Two nights ago, my production site was at 7.0.6 & loaded with customizations. I decided to clone it to a new VPS, back up all database tables & uninstall all third party modules. Following the upgrade path I made my way to 7.0.7, then 7.0.8 and finally 7.0.9. So far, so good. They really made that part of the process pretty painless (I suppose removing all third party modules helped here).
7.1.0 B1 upgrade also went smooth, and B2 was no different. With my production data (clone) now at the latest version, I pulled the third party modules that were also at that level. Installed the modules & re-imported the database tables back to regain content.
About 30 minutes ago, I decided it was good enough to switch over. If I had waited any longer, I'd risk a lot of the production database being out of sync due to new content/members. Some damage control was done here by removing upload privileges to all members temporarily.
You can get a look at my production 7.1B2 site here. I have many loose ends to tie up, and some modules are still pending 7.1 compatibility before I can install them.