Afraid to make the leap to diesel

To me the question is not gas vs diesel but what size MH do you want. For most of us buying any MH is a big purchase and you want to get the "right" one. If you want to stay small 34 ft or less I think a gas MH makes more sense. 36 ft to 43 ft a DP makes more sense. What I have noticed is that the bigger the DP gets the bigger the eng is and the more HP it has. A gas MH has the same eng whether it is 30 ft or 38 ft. Having raced motor cycles you understand that it is the HP/WT ratio that determines performance. A 30 ft MH will have 362HP and weigh 15,000 lbs a 36 ft DP may have 360-380 HP but weigh 28,000 lbs. A 40-43ft DP may have 500 hp but weigh well over 30,000 lbs. A 32-34 ft DP if you can find one may have 190-300 HP. So if you want to stay small like your older 30ft Allegro a 362HP Ford or a 340 HP WH will in general will have better performance than most DP's. The decision is harder in the 34 to 36 ft range.