Looking for Diesel Experience

I am moving up from a Fleetwood Bounder 34B to a diesel.  I am focused on either the Dutch Star 4018/4081 or the 4369.  Couple of questions.  Does size really matter lol? I am aware of the differences in layout and larger bath but more curious to hear about drivability and availability of campsites. Do you really feel that extra 3 feet? What were others experiences in going from a gas to diesel? Big jump for me going from 35ft to 43ft. I am a little hesitant going to 43ft and may stay with 40ft. Thanks