I usually run the MD off the desk, cos the audience rec needs all the help it can get
IMO the lack of quality of MD is less obvious on s/d recs, cos the source is relatively pure.
If you use the JB3 for the desk, the MD audience rec will suck bigtime in comparison
Of course I really want another JB3 (or an Edirol) so the problem wouldn't arise.
Hope it worked out, whichever way it went