There are a lot of folks that like their gassers, a lot like their diesels. I'm in the latter camp. I towed for years with a gasser...didn't like the cost in buying or the "cost" of owning. When we had our 5th wheel, I got a diesel truck (Ram Long Horn with the CTD) and will never tow or haul or push any weight with anything but a diesel. I'd even like to have diesels in my cars, but, the European versions are the only ones that you could get with a diesel (Dodge Journey and a Jeep Trail Hawk).
Now that I've got the motor home, I couldn't imagine it without a diesel (42' and 38,000 lbs as we travel). We have already "talked" about what we will do when we get older and don't need or want the big motorhome. A smaller class C would work better for shorter trips, but, you can bet it will be a diesel...
There are lots of threads about the pros and cons of each type...I won't go into them again, but, my vote will always be for a diesel; whether powering a motorhome or towing a bumper pull or 5th wheel. As for the generator sitting in the front of our DP? Can't hear it hardly at all when parked (it is just a "humm" and we don't need to turn up the volume on anything) and if it didn't have an "ON" light, I'd never know it was running when going down the road.