I have a 2004 Coachmen 354MBS 37'. I have owned it since 2006 and I am very satisfied with it. I checked the fuel mileage on a trip around Northern CA a couple years ago and I got over 9 mpg pulling an IH Scout. I haven't checked it since and probably won't ever, 9+ is good enough for me. The 300hp Cummins pulled the Scout without any problem. The hills weren't a huge challenge, not to say I didn't notice them, but, I was happy with the performance. Towing or not, I drive as fast as conditions permit. Would I like to have 4, 5 or 600hp, hell yes, maybe in my next MH.
When I bought this MH it was within my budget. I knew what I could spend and I looked around for quite a while before I bought. Having had a couple of older MHs I also knew what I wanted in the way of a floorplan etc. The coach has a single deep living room slide, decent kitchen counter space, adequate bedroom, a big vanity counter top along with a nice sized shower and dressing area, a priority for me. I picked this over some gas units that were higher end and some older diesel units that didn't have the layout I was looking for. I am happy with the build quality, no issues other than a couple of drawer guides and some little misc. stuff that I took care of myself. No "house" build issues!
I have however had a couple issues that were Freightliner related. I had a leaking oil seal on one of the front wheels and an air dryer on the brakes crapped out. The most significant issue was on a trip through Oregon when ALL of the bolts fell out of the flex plate. I stopped at a campground for a couple of days and when I packed up to leave the MH wouldn't move. I had to be towed 90 miles, thank you Coach Net, and spent a couple of days in the shop for repairs. These problems were all fixed under warranty and all cropped up under 12k miles. This same trip my friend's 40' Country Coach also had to be towed to a shop and he lost a couple of days with a fuel delivery problem.......they can all break!
I have had a few 10 hr days behind the wheel and one 15 hr stint and didn't feel beat up when I was done.
To sum it up:
Not at all fancy, very comfortable, drives nice, pretty roomy, decent storage capacity, everything works well......I'm still satisfied. I might look around for another coach now that I'm retired, but, maybe not.