Funny thing it only iced up in Utah, maybe altitude played a part in it, we were at 6800' elevation and it was dry. I have had it running on hot 90*+ very humid days with no icing. My Refer had conked out a few times on the way through Utah and CO, and only above 5000', found out it was due to altitude, worked fine once I was onsite though.
I was looking at the Dometic Penguin II, but couldnt make out what the interior was supposed to be, just looked like a panel. I will check out the Mach, looks to be just the height I need.