re: Luxurylite cot--while it weighs the same or even a little less as a thick thermorest (the 2 inch thick ones, 5cm) I see the main downside as being it being hard on a tent floor with small sticks, stones, anything sharp under the tent--which could and probably will end up with some puncture holes happening to your tent floor, which aint a good thing as zee water she a come in.
Its so important for a tent floor to keep hard objects off it on the inside, especially something so narrow as these support rings with your weight on it.
Also, Im a keep it simple sort of camper, so couldnt be bothered putting it together (Im thinking more travelling, where you have to do it each night)
for me the thick thermarests are very very comfy, so that would be my "total luxury" thing. I recently was car camping and biked about 80k to a friends place who lives in a nearby small city and I put my big thermarest on my rear rack to sleep on at his house. They roll up still quite big, about 2 feet long and the roll being at least 6 inches thick, so it takes up an entire rear rack and more hanging off the back. But I did sleep well at his house as my back had been sore from helping a relative move some furniture a few days before and I didnt want to sleep on his droopy couch.