Does anyone have experience with the Membership 2 member

Does anyone have experience with the Membership 2 member import?

It wants a file but does not indicate what format the file needs to be in.

I was hoping that I could just import my existing BuddyPress / WordPress users in one fell swoop, or have a drop-down list of those members that I could select [cntrl-click] to import, but alas, not. I have to hope I remember everyone's username and search on it, or open two windows and cut & paste back & forth into the import search window.

It would be really nice [staff: HINT] to be able to import cvs file, import all BP/WP users (for existing big member sites) or choose one-or-more from a drop down box.

Any suggestions as to importing other than the cut & paste into the import search box from the current WP members?