I own the Caribou MF. It’s an incredible bag. I use it from late spring - early fall. I can turn from one side to another w/o the bag moving with me. I can also bend my knees as well. The 38* rating is pretty accurate, although I’m a warm sleeper. The bag compresses to the size of a nalgene bottle. I’m not a fan of compressing insulating material that small when I don’t have to… so I use a sil-nylon stuff sack that’s about twice as big as the one that came with the bag. It’s also nice as it fits well in bottom of my GG Vapor Trail.
I’ve never used the Megalite. I’ve used the Highlite and it was just a bit too constricting for my taste. It fit like a glove, but was not easy to turn w/o somewhat fighting with the bag to move with me. So, I only use the Caribou now. It’s only 4 oz. heavier and tons more roomy.
guru