I've done both. Went from a fifth wheel to a gas class A, to a dp and back to a fiver. Everyone has different experiences but our first gas motorhome was a nightmare to drive. I gave up and got a lower, mid level dp. It was much better but still required about $4K in mods to make it comfortable to drive long distances, including Koni shocks, Safe-T-Plus and front and rear stabilizer bars. We had some good times with it in 7 years but I got concerned about long term costs of repair and maintenance. New tires were over $3k.
When it came time to replace the motorhome we compared the prices, features, options and perceived quality of a new truck and fifth wheel with a new diesel motorhome. I think what we have is pretty good and my total outlay is not much more or even less than some gas class A's and a lot, lot less than most comparable dp's. I would say going down the road is much more fun in a motorhome if you're not the driver but when we set up for the night they are all just a house on wheels. Just my experience and opinion, which has nothing to do with anybody but me.