Note that the "M/S" in that LTX M/S2 tire of course means Mud & Snow ... it means a tread with better traction just in case you find yourself on wet, soft, or snowy surfaces.
The XPS Rib tire has a smooth tread for long wear on relatively firm and dry or non-slippery road surfaces. The steel sidewalls are to help with scrubbing against curbs in commercial use.
I'd definitely go with the LTX M/S2 tires on a Class C motorhome so as to be ready for the widest possible conditions anywhere anytime. I have them all around plus the spare in size 215/85R16 LR E. I changed to the 215/85R size to get a slightly taller tire for better ground clearance. The M&S tread - even though more aggressive than the XPS tread - is still very quiet on the highway.