I’ll try to be brief ~ I have an XLC with a very custom Wookie - 0 degree with lots of extra filling - it’s amazing how much warmer you are with this UQT. My question is ... should I GO for the under cover protector? Hi actually think I already know what I want to do number one it protects the expensive under quilt and number two it will surely help with a couple of degrees added warmth. I’d like to hear from some people that have also opted for the winter top cover a.k.a. the Chinook. Regardless of how cold it is an even with my thunder fly tarp hanging above me it is nice being able to have the fresh air and to also be able to see my surroundings end to those of you who have the Chinook is it a little claustrophobic? I’d like to hear some input from other owners ~ this will help me decide whether to place an order or not thanks in advance for everyone’s input and guidance