The Sphere is lightweight and warm. The wave-shaped box wall construction is meant to stop the down moving about and cold spots forming. I certainly haven’t noticed any of the latter but then I haven’t in most of the other bags tested either. The shell fabrics are thin and soft and drape well round the body. The hood fits well. However, the Sphere is very close-fitting. I can’t turn over inside it and felt slightly restricted and I’m not heavily built. I think this is a bag for skinny people and those who like a bag to move with them rather than being able to move in it. I also found the zip a little hard to open when under tension, which has once led to a feeling of being trapped when I was too hot inside and couldn’t move for a short while.

If you find the fit comfortable the Sphere is a top quality bag. I prefer a little more room.

First published: July 2013