I had both diesel and have not had any major engine problems with either. Either engine can fail without the proper maintenance and operation by the owner.
Right now I have a gas coach because it is the right coach for me now. Next year maybe a diesel suits my purpose better, as they have in the past. Or, it may be another gasser, depending on what I need. We spend a lot more time LIVING in our coach than driving it so to us the floor plan is still more important that the engine. We have never towed more than 5000 pounds so having a larger towing capacity is not a plus. We have also driven through most of the high mountain passes out West with both the gassers and the diesel engine rigs and we made it to the top and back down with both of them. You have had three V-10's so what was the mileage when you got rid of them? Paying a premium for a coach that can go hundreds of thousands of miles doesn't make much sense if you trade them out below 100,000 miles. Your V-10's each should be able to log 250,000 miles with normal maintenance and sensible driving practices.