The benefit I see with the single is that I never had to fiddle too much in the middle. With my two skins now, the tarp is large enough that I have to work it in, and when I do that with the second for an overlap it tends to push the first one away since it's stuffed full. Never had that problem with my single, but then again that one was larger and didn't get as stuffed.
For the hammock, I've gotten lazy slugs. Used them for the first time on my fishing trip about a month ago (trip report
), and will never look back. The ease of set-up, not having to pack away your quilts and hammock separately, is superior.