Lots of good points of comparison. I was going to be the 1st to comment, but had to go and am just getting back over 3 hours later. But when I read your 1st impressions, I was just getting in from a backyard nap in the BMBH UL in one of the most beautiful days I have seen this time of year. It was downright coolish with the wind chill! I was trying to read a book on my Kindle and I passed out. A neighborhood dog playfully running around my hammock woke me up, I was afraid he was going to steal one of my Crocs!
So I guess you have the BMBH with pad pocket, and not the UL? I have both JRBs. I noticed once again that the UL has less forced curve in the shoulders (and a bit more shoulder room) than the deluxe. And it has a better view, really a lot more so than the deluxe. But I'm not sure how important any of that is for me, I really get by shoulder wise OK with the deluxe even without a pad, and I usually don't get in it until bedtime anyway, so not much looking around. And I do love the pad pocket in the deluxe. But the UL does save about 1/2 lb. I'm not certain yet that I really like the UL any better overall than the deluxe even with the increased shoulder room. There is just something- other than the pad pocket- about the deluxe, that I like, or maybe I am just used to it. I do feel that I can find more usable book reading/lounging positions in the deluxe ( actually, mine is an original, not the zippered Deluxe, but I think they are VERY similar). And when it comes to lounging, I have only so far done this with the original model, I don't think I can do this in most hammocks:
I know what you mean about "One nice thing about the higher sides on the BMBH was that when laying on your side, it was comforting to have an edge for your rear end to lay against, giving me more confidence that I would not be falling out anytime soon." The sides are so supportive that I can lounge like in the above pic, leaning back with chair like back support. The UL model still has a lot of this side support, but not as much.
Another thing I am waiting for winter to check out in the BMBH UL, and wonder about even more with the WB RR: ease of keeping quilts tucked. Last winter I became aware of what seemed to be an actual benefit to the lack of side/shoulder room in the BMBH, the aspect that caused the most complaints. This half pipe shape actually tended to "funnel" the quilt down to my sides. The UQ wrapped up well above on both sides and well above the edges of the UQ, whether it was just laying loosely on top of me or tucked under my sides. It just started seeming to me that I was having a much easier time avoiding TQ drafts compared to my non-bridge hammocks. Sense my BMBH UL is not as deep and is a bit more "open" in the shoulders, I will be interested to see if it works as well in this regard. I am also curious about the WBRR in this regard.
Again, good comparison, keep us posted.