What is it you're looking for in a MH????
Right now diesel is about the same cost as gas....at least where I am.
Depending on the MH, MPG MAY be better than a gasser. but this is very model specific.
If a DP, really really quite while driving.
Most, if not all DP MH have air suspension which is a great ride.
The ability to use truck lanes for refueling is priceless.
DP are more costly to maintain since they hold quite a bit more engine and tranny oil but the difference is only the cost of the fluids.
Needless to say I'm a fan of the DP's.