How do you record in mono with Metro 6.3.5.6 (or any Metro 6)? Yes, you can "split stereo tracks" after recording and use the left track, but it is very annoying to only hear yourself in your left ear while performing...
If I try to record to the new mono track (which I only can seem to create with "split stereo tracks"), it says that the source and the destination must be of the same type. I can not find any way to record in mono in the Metro or OS X (10.3.9) settings!
Except for this one problem, the setup works great. I'm using a M-Audio MobilePre USB, by the way.