Diesel --- front engine -vs- rear engine

Wow! I have a Tiffin Allegro Bay 35TSB FRED (340 ISB with 6 speed Allison). It has been a great RV. Engine noise is minimal. No problem carrying on a conversation or listening to CD's. Not sure why the sound issue keeps popping up. The engine brake is loud going down hills and the auxiliary cooling fan is loud when going up steep grades for long periods. I've been getting 9.65 mpg towing a Saab Convertible on a tow dolly in the Northeast. Down south where it's flatter, I've been getting 10-11 Plus mpg. I've been looking at other floor plans recently in diesel pushers. Only problem is that I'm really happy with FRED and our current floor plan is great for us. Getting 6-8 mpg in a pusher has held me back also. Eventually I may purchase a pusher once I see a floor plan that better suits us than the 35TSB. By the way, I did install Bilstein shocks and air bags to improve the handling and ride on the FRED. The ride in the FRED is firmer than a pusher, but probably similar to a gasser. The Bilstein shocks and air bags have made a big difference.
Obviously the pushers have more storage and I assume are considerably quieter. The ride is probably significantly better also. This is our first RV. It's our 8th season with our Bay. So far so good.

Art