anytime I've transported Class A's from the factories to dealers, I bristle when one is the type or brand that has the 'fill' in the 'middle rear' of the coach, as this is simply the hardest and most aggravating place for a fuel fill on any rv... it's makes little sense for the owner as you have to 'guess' whether you are in line with the fuel hose, and really have no way to know even if the hose will reach until you park, get out, and find out you have to pull up ANOTHER 3 feet, and get 4 feet closer to the pump!
Class A Diesel are by far the easiest - the fills are on either side, right next to the driver or passenger seats..... easy!
but, while it can be aggravating for sure, I wouldn't let that alone determine if I were to buy an RV or not - the floor plan layout is the primary concern.
'14 Thor Palazzo 33.3 compact diesel
KingTailgater2 Dish, 100w/5amps roof SOLAR, BlueOx, 100,000+mi since '14... US, Alaska, and Canada... GA, NC, now N AL : )