My opinions after attending MRAP U at Red River Army Depot, Texas.
RG-31: Great ride, smooth handling, handles a 60% uphill and a 30% side slope just fine in low range, cramped interior, questionable air assisted doors.
RG-33: Great ride up front, in rear it feels like the back end is fishtailing around corners and bumps. Good power, can do 60 on perimeter road in the straights, plenty of room, bus like forward seating and best in class visibility.
Caiman: SUCKS, Steering is very sloppy (it's all the joint's we're told. On a brand new truck and it WILL get worse over time). Rear suspension sounds as though it's beating itself to death when riding in the rear of the truck. Brakes are weak and it wander's in grooves really bad. Seats were comfy though. Class behind me rolled one into a ditch and all 9 occupants were MEDEVAC'ed , 1 suffered a broken neck, 3 suffered broken bones, 5 were treated with minor injuries and released.
Cougar: Drives great, good power, runs down the road just fine. Seat's were comfy but visibility leaves something to be desired.
M-ATV: **** fine MRAP if not for the visibility issues. Runs to 70 MPH with no problem on the perimeter, corners great, common drivetrain (C7 and Allison combo) and climbs the 60% incline with ease. Awesome A/C.
IMG MaxxPro: Good driving truck, built off of a proven drivetrain, A/C is horrible, wallow's like a pig in mud in the corners but the undisputed mass produced MRAP. IMG has put out more of these than the other Mfg's combined.
My Ranking, M-ATV, RG-33, Cougar, RG-31, MaxxPro, Caiman.