Bought this because our English springer spaniel had some shoulder stiffness after very long walks using a Ruffwear Front Range harness (which is otherwise excellent). The hope was the attachment point further back and additional cross straps between the front and rear straps would spread the load and eliminate the shoulder stiffness - and it seems to have worked. 27 miles over 3 days in the Lakes (including a 12 mile/3,000 ft day in Eskdale) and no signs of any stiffness or soreness. The attachment point being further back also works well for control, including controlled descents down rocks and stiles! As a relatively slight 17 kg springer, the medium size is close to being too big on the shoulders (plenty of space to get broader as he gets older), but perfect around the chest. Seems very well made.