Quality of the seats notwithstanding, the nice thing about the MH is the ability to move out of the co pilot seat and travel in a recliner or on the bed if you need to decompress your spine and relax, whereas the 5er the law prohibits riding it so your only option is the TV.
Class C = Van cutaway chassis and so the interior is very similar if not the same as the HD pickups of that brand. Class A DP's built on a bus chassis are designed to accommodate air ride seats and other options designed to keep professional drivers comfortable for a whole shift.
