I have a Mountain Hardware Lemenia 30 degree bag. I’ve had it for fourteen years now. Packed it’s about nine inches long, about six inches in diameter (I can make it a small ball if I want). Synthetic as I do a lot of backpacking and learned long ago that a wet bag sucks, a wet down bag sucks a lot. I needed a bag to do both Moto-tour and backpack. Easy to pack, light, easy to clean, and obviously long lasting (durable). I sleep warm, so a thirty degree bag is way too warm most of the summer, just warm in the fall, and pretty comfy in the early winter.