A double wall (DW) design will most often end up being more comfortable in the long run, than a single wall design, to spend time in. No doubt about that.
That said, with just me sleeping in the very well ventilated Rainbow, in the clouds all night, in very moist western Washington, I wake up to very little to zero condensation in the Rainbow. In dry climes (most of which are dryer compared to Western Washington), I think condensation with be even less of an issue. I can also get all of my gear (pack, boots, and large longrange rifle) in and on the tent floor with me if I deem necessary for some reason due to the very large and comfortable floor size for a single person tent.
The difference in the square footage of the floor size between the 23 ft. square Rainbow and 18.1 ft. square Moment DW is enormous. To put it in perspective, the Rainbow floor space is 27% greater than that of the Moment DW for no additional cost in weight. More space for the same weight equals more comfort and relaxation and rest when using your shelter, which can translate into how well you can sustain hard hunting.
In addition, the height of the Rainbow is 44" as opposed to the 39" height of the Moment DW. Again, this translates into more comfort while using your shelter.
The Rainbow is simply a much larger shelter in head room and floor space for the same weight as the Moment DW and I have had zero problems in the worst of moisture conditions with it. The Rainbow also has a large and very adjustable vestibule. In addtion, with it's true 40" continuous width, two standard 20" pads can be placed side by side so it can work for two people in a pinch if that became necessary.
Additionally, the Rainbow can be made to be freestanding if trekking poles (something you should already have with you) are used at the ends at ground level to tension the floor widthwise as is shown in Henry's video for the Rainbow. I use my trekking poles everyday and so if I was somewhere that I had to have a freestanding tent, I would simply weight the collapsed tent with some rocks or something while I was gone hunting for the day. But, I would do the same with a freestanding tent. You would obviously never leave a freestanding tent freestanding while gone for the day--one gust of wind and there goes your freestanding tent. So, you wouldn't treat the two much differently if in an area where you couldn't stake them down.
I've seen staked, otherwise freestanding, and partially loaded tent be blown into a crevasse while their owner was away summiting (ahem...'I have this friend'...
). This kind of story is pretty common in mountaineering circles and the typical solution is to use trekking poles and crevasse rescue pickets for stakes and/or load snow onto the collapsed tent with your snow shovel before leaving camp for the summit. Typically, you may want at least your crevasse rescue pickets with you, if someone fell into a crevasse and you need to set up an anchor to get them out, so the best solution often ends up being to simply pile snow onto the collapsed tent while you are gone. I'm not aware of a pretty, perfect solution to this dilemma, freestanding or not no matter what kind of terrain you are in. And the Moment DW requires an additional 7 oz. pole to make it freestanding, making it significantly heavier than the Rainbow, when you can accomplish the same by using trekking poles when in the tent at night with the Rainbow.