We have a 35QB4, so I can't answer specifically to the 37BH. But hopefully I can answer a few of your items.
1) As of last year, the 35QB4 did have the 12' Super Sofa available. It never was shown on the floor plan, but it was listed on the build sheet.
2) We like our floor plan. For us, the bunkhouse space was a priority over the improved layout of th common area space on th 37BH. Plus, we didn't care for the exterior bathroom door being on the non-campsite side of the 37BH.
3) I ran a 3500 dually for 11 years, and then traded for a 3500 single before the new trailer was on the radar for us. After the first long pull I was wishing for the dually back. We're within weight limits, but the stability isn't there with crosswinds. A 40' trailer will really push the tail of the truck around. An SRW will do it, but the DRW adds a whole different level of confidence.
4) Ours came with a grille for the outdoor kitchen. It hooks on to an aluminum bracket on the side of the trailer and plugs in to a propane quick connect fitting located behind the slide out skirt. Not sure what happens with the 37BH.
7) As of our 2014 model, no awning LEDs.
8) As of our 2014 model, no genny prep available. Two 30 lbs propane tanks.
9) Love the Level Up system. No problems so far. Makes setup and tear down a snap. Actually was the deciding factor in choosing the Silverback.
10) We upgraded to the Trump mattress, which we really like. Kept it a queen though for walking space in the bedroom. Went with a single AC and a Fantastic fan in the front bedroom. We full timed this past summer, and even though the nose was pointed into the afternoon sun, the bedroom was still cooler than the main area. Probably an okay setup for the northern half of the country. We also had them add a table in front of the left side sofa in the bunkhouse. Good for coloring and puzzles on a rainy day without cluttering up the main area. Plus a bunch of stuff I added, like a surge protector, keypad locks, Oxygenics shower head, and some other misc. mods.
Anyway, I hope that helps. Let me know if you have any other questions. Good luck on the camper search!
2014 Silverback 35QB4
2012 Ram 3500 6.7/slushbox