I've been putting finishing touches on UMMD- I made the lower front panel from a clear sheet of polycarbonate which still has the protective film on it- I'll peel it off at the MakerFaire so it will look nice and scratch-free, at least for a few hours. The panel is held in place by magnetic strips, like SoM.
I replaced the Chinese belts in UMMD's XY stage with Gates LL2MR09 belts, and did the same in the X axis of SoM (then had a problem with the extruder motor not turning, which I will check out this evening). I did some before and after test prints and can't see much, if any, difference in print quality. One thing I discovered in this process is that UMMD can print at 250 mm/sec, at least on long straight runs.