Let me just start off by explaining that I "never" car-camp, but I decided to try the Vesper at one of our local Provincial campgrounds, instead of testing it out on trip, only to be disappointed in the middle of nowhere. My first morning, I woke up to car doors being slammed, families being way too loud, and other noises, and that is when I discovered that I had slept in until 10am!!! (here I thought people were just rude, nope, I just slept in) I never sleep in, and especially camping. All this to say that I was pleasantly surprised to the quality of my sleep. I normally wake up having to vent, and found this set up a little easier to control temperature. I seriously slept super well. I have since taken it out on trip and find it very light, and plan on adding this to a sleeping bag to increase the range in the cooler fall, and winter months.
It's not cheap, but I am certainly glad I picked one up...saving up for the cooler range as well. :)