As one that has driven both, here are my thoughts:
Air ride means the diesel will ride much smoother, with less body roll in the turns. Quieter, too, with the engine in the back. Definitely more power on hills, and towing is more effortless, although that depends on lot on just which diesel engine, and which motorhome. There are some underpowered diesel Motorhomes out there.
In terms of throttle response, acceleration....That is where the gasser wins in most cases, hands down. When you 'step on it' with a gas engine, it will downshift, turn a bunch of RPMs, and get going quicker (although can be loud). Do the same with a diesel, and it grunts, gurgles, lugs, and slooooooowly accelerates.
Sooo, yes, there are differences in how they drive. All I can say is, take each for a test drive, and decide for yourself.
