Re: Describe â€œwhat you get,â€ please!
the only reason that bp should break your WPMU installation if you turn it off would be if you left the bp theme set as your blog’s theme. So long as you remember to change your theme back to wp-default or another wp theme, you should be fine.
you will have one MAIN blog that will be bpenabled. you can set multiblog=true to enable bp on all of you blogs. This means that if you go to domain.com/members/username, and then go to a sub blog like test.domain.com, you can go to test.domain.com/members/username and you would get the same screen. If you do this, all blogs need to have bp enabled themes to work or elss links will break. Otherwise, your nav bar on top of your screen will always link to your bp root blog.
Hope this helps.