MHC 375FL owner here. Your models (376FL and 377FL) came out the year after we purchased our 375FL. The floor plans are (almost) identical, except the 376 and 377 have the loft over the master bedroom. And the kitchen counter is slightly different. Even the 374 and 375 models and floor plans have the refrigerator and kitchen table swapped back and forth in their positions.
Still, when the 376 and 377 came out, I got a little envious and kind of wish I would have waited another year and got the 377 (residential refrigerator). So, I've been following threads about the 376 and 377 and this is the first one I've stumbled into that addresses the rear drop down dragging. On mine, I never had the problem of the rear dragging, but the rear jacks drug way too many times. I ended up raising them as high as I could (about 4 inches), and that pretty much stopped the dragging. Those poor things were getting pretty beat up. I lost one foot pad, so always remove them when traveling now. Those foot pads cost over $50 each to replace. That pretty much took care of my dragging problem.
With the length of these campers, another problem is parking on unlevel campsites (unlevel front to back). With the shear length, even a slight incline can cause the rear to touch the ground while the front is high in the sky, or just the opposite with the nose on the ground and the rear in the air. This was also a problem I had to over come, but found adding boards under the tires to raise the entire trailer higher often takes care of that and provides enough clearance on those sloped campsites that the trailer can achieve level.
Also as stated above about the quality of the 376, 377, mine was no different. I had over 80 items in the first year of ownership what required warranty work (serious stuff like wheel hubs and brakes that fell apart), to simple stuff like trim and cabinet doors. Much I fixed and repaired myself. The rear closet completely collapsed on our maiden voyage. It took 2 attempts to finally do a repair to took the shelf and cloths rack from collapsing. It's since never fallen again, and never will the way I rebuilt that closet.
Like you guys, the floor plan cannot be beat. It's a great floor plan. And the back door on the opposite side has been fabulous for us. We had an awning installed over the rear door, with a LED light strip that matches perfectly the front awning. We use the back door 90% of the time. Love that door on the opposite side.
Mine tows pretty level. My dealership did a good job on setting me up with the right hitch and adjusted the king pin height. Still, that did not stop the rear jacks from dragging. I'm towing with a Chevy and evidently mine sits lower, so I don't have that unlevel problem. However, I have only about 5 inches of bed rail clearance, and I have made contact a couple times. I was able to fix the fiberglass cracks myself, and you never knew what happened, you'd never know or see it now either, my repair turned out pretty good.
One thing is certain that I completely agree with another post above, once you've experienced this floor plan, nothing else matches it. (especially the use of that back door on the opposite side).
Not the best photo showing the back awning, but is is about the only one I've got available at the moment:
