Getting the right mid-layer can be an important part of a good days walking, too thick and bulky (too hot and uncomfortable), too thin (cold and uncomfortable), or wrong fit (bad days walking)
This is a really versatile jacket, which can be worn in many differing conditions. PWW undertook a field trial with walks from 5 to 15 miles, covering around 50 miles in total. This was across Hills, Fells, and Trails.