Well I finally got a chance to try out the pluq, and I must say I was comfortable in the lower thirties with mine. I was bundled up so I cheated, but I did slide a second poncho liner inside my pluq and it worked ok. The only issue I had was that the shock cord I had worked well with one in home as a test run for the weekend hang, but as soon as I slid the extra liner in it I got a helluva sag with the uq goin. I still manager to stay nice and toasty inside my sleep system but the liner was hanging about six inches under my buttocks. Luckily no CBS, but if I had gone much colder I would have been miserable.
My entire sleep system was a little different. I was car camping so I didn't have to carry my stuff anywhere. I took 2 fleece blankets with me. One went in my sleeping bag (30 rated) footbox, and the other was draped over my srl as an insulating cacoon. I had my tarp pitched low, and of course as I said I was bundled up. I had a polartec lined gortex jacket, a polartec under that, underarmor longjohns, and two pairs of socks.
I did not take the camera withthis trip and the iPhone died on me, but it was a great hang for me. Definitely sold on any kind of underquilt, they are the way to go!