We decided on the 21C for thses reasons: :
A. we like the rear dinette..and didn't want to sit in front and look at the road, or bath house or back of our truck. WE usually prefer the rear view
B. we measured and estimated the 'walkaround space' at the rear bed wd decrease our interior storage by about 20 cu ft
C. we like the extra room in the walkway to get 'past the kitchen area' and don't mind the smallish front bath, bks the side bath encroaches into the interior space and it kinda made is feel as if we were still in our old Casita.
D. with the center open area of our C model, we have actually used a std 'Pak n Play" crib for a young grandchild.
Therefore the C model works for us.