ECGManager, Let's see if I can answer your questions.
Speed up hills/mountains - Most times I don't even know I'm going up a grade & I'm pulling a Roadmaster dolly with a Hyundai Elantra on it. I turn on the rear view camera to see if it's still back there.
Front bunk head room - I have the front entertainment center. I finally got the ladder and pulled out the front bunk. I'm 6' 2" and I cannot sit straight up on the bunk without my head hitting the ceiling. It's NOT a tight fit, I just have to slouch a little to be comfortable.
Fuel range - I drive about 500 miles then start looking for a fuel stop. Usually about a 45 -55 gal. fill up. I drive mostly tertiary roads, so my foot is not mashed against the floorboard!
2014 Golden Burgundy Seneca 37FS