I have the MM 3 2.0. Definitely expensive but worth it for me, since I also brew in 1bbl batches. I can grind 100 lbs of grain in 10-15 minutes. For a 10 gallon batch it only takes a couple min. But the great thing is it doesn't jam often, and when it does I can fix it by jamming a ruler down the center so the roller's "grab" again. Once it grabs it doesn't stop. Sometimes it won;t grab in the very beginning. The problem I had the the BC was that, after a year or so it would stop grabbing mid grind.
Oh, I've had the MM for about 6 months.