the question of whether a Class A gas motorhome is 'too loud' while driving can be a personal one, meaning that everyone may have a differing approach and past experience that impacts their feeling on it... I've owned a Ram dually diesel turbo pulling a 40' Blackwood fifth-wheel and certainly understand the 'noise' that can be associated with especially the take-offs in early gears, and the sometimes screaming 'up hill fights' when hills and mountains are involved.
I've also owned a '15 Georgetown XL and didn't necessarily feel any ill-will toward it's Ford powerplant - it seemed to drive great and I don't remember 'disliking' it's sounds.
I've also delivered many brand new diesel and gas Class A motorhomes from the factories to dealers all over the country, and find that I rarely had issues with the 'noise level' of the more entry-level gas coaches, like the Coachmen Pursuit, the Coachmen Mirada Select, the Newmar Country Star, the Newmar Bay Star, etc.
I think some will find most any Class A gas motorhome as 'loud', regardless of the 'FORD' version of the insulation factor, or the Manufacturers name on the front - they all originate from the same Ford factories. While some RV manufacturers 'might' add additional insulation, it's doubtful it's a dramatic swing one way or the other. You can certainly add modifications yourself.
I wonder why GM and RAM don't get in on this RV Class A thang?
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
100,000+mi since '14 - US, Alaska, Canada - Hiawassee, GA! (also, '14 Gulfstream Amerilite and '07 ForestRiver Rockwood) : )