Is Radiant+multi-site the right combination?

I’m interesting in building a site with capabilities similar to those of
WPMU + Buddypress but with Rails. Will Radiant’s multi-site extension
provide the same multi-domain creation capabilities that WPMU offers?
Essentially I’d like to build a blog hosting platform w/ social
networking functionality. I’m hoping Radiant is the right platform to
build it on.

Thanks for any and all replies in advance.