Wow. This stuff looks awesome. You guys don't disappoint.
Do you mind the extra weight? I think if you're using a sled the extra weight is worth it.
I also think the added comfort can easily be justified. The ability to retreat to your 'tent' and relax in your hammock without having to deal with the freezing temperatures makes this all doable I think.
Further, in case of tragedy, this means I can dry my clothes ...