Hey guys, I have three of them. Although I can't comment on winter warmth yet, my fiancee and I have used them for a combined total of about 30 nights. We used them in Glacier NP for a week, and the rest of our camping was done in Wisconsin.
We both have the lighter, thinner 30D material, and so far, no durability issues. No leaks. One pad had a valve that leaked very slowly, but I think it was a fluke because I just added another rubber O-ring and it fixed it.
My DAM's are easy to blow up with the Big Agnes Pumphouse, but I've replaced the included short piece of tubing that serves as an adapter with a much longer one that stays in place better (the pumphouse can't fit around the larger valve for the DAMs). It was an easy fix, and not even necessary.
The DAMs deflate slower than non-DAMs because of the feathers, but its not that bad. With practice you can get them deflated and packed in a couple of minutes.
I'm excited to get to try these out in cold temps this coming winter. I will say that they're not as "easy" as say a Big Agnes Insulated Air Core because of the pumphouse and slower deflation time, but with the weight savings and gained warmth, its worth it.