BuddyPress.org

If you can wait a few months, you could wait, but by then everybody will be talking about BP 1.3 and WP/WPMU 3.0.

I tried to upgrade from version 1.0 to 1.2-bleeding edge and quickly ran into trouble. I’m now upgrading to 1.1.3, which already is costing me longer than I’d like.

But at least 1.1.3 is somewhat stable. If you’re actually going to use your site, there is a lot to be said for staying one generation behind.