Had the challenger version for 4 days last fall in corn. Nice machine, but it's big and heavy. With the big tires on rear and RWA we couldn't turn and come right back in on the end without backing up first. Expected the unload rate to be super fast, but it was not any faster than my R62. A number of sensors not working and beeping all the time and several updates added before we could use it. typical of a new model, I would wait a year or two for them to get the "bugs" out of it before getting serious about buying one. I would expect the two smaller versions to be more reliable since they have been out a while as MF and challenger machines. Along side the R62 it looked twiced as big and I think it weighed twice as much too. The corn head ran at a much steeper angle on it and there was no way to tip it back on the feeder house.