You say your size limit is capped at 35 ft. So to me the shorter you go say 30- 34 ft I would look at gas, over 36 ft I would look at a DP. At this intermediate size the decision becomes more difficult. Another thing to consider is that on a gas MH it is the same HP eng whether it is 30 ft or 38 ft. A DP may have 400 hp on a 38 ft but 300 on a 34 ft. So in general a 30 ft 362 HP gas that weight 15,000 lbs will have better performance than most DP's of the same or less HP and twice the weight. HP to wt ratio will determine it performance. Some on here have found short DP's (34 ft) that they really like. I would not buy a MH just for the eng but rather how you plan to use it and the type camping you like to do.