I love the clark system, but I am 6 feet 5 inches tall and I pretty well max it's length out. So mine is for sale and I am going to buy the new longer one. The pockets work really well for insulation. I have taken mine on one hike and I stuffed leaves in the pockets and stayed very warm in about 35-40 degrees. I also have a hennesy but you have to add a lot to it to stay warm on a cold night.