Homegroups is an absolute mess. No doubt about it. The idea is sound - but not being able to be backwards compatible - its a fairly large step that needs to be implimented better. They are getting there.
Between 2 7 boxes its still a bit wacky - but not really horrible. I really would like to see how it does on a domain - but work won't let me put it on there for a test .... yet.
This might be a good time to live by the rule its better to ask forgiveness than it is to ask permission. However, I will have to do it on a test domain if I play that way.