Recently traded in an Adventurer 35U (gas) on a Forza 34T (DP). Both coaches are about the same size, the Forza is about 2k heavier. Both have about the same horsepower. Have pulled the same toad over the same roads. I can tell you I definately prefer the DP. I feel much safer, smoother ride, better brakes in the Forza. In Colorado, its 30 mph at 4000 RPM(gas) vs 45 mph at 2000 RPM(DP). Also 6 mpg (gas) vs 10 mpg (DP).
We live in ours 9 mo/yr so floorplan is important too. Keep looking, maybe you will find both; your floorplan in a DP.
Good Luck