At 5'10", 165lbs I ordered the medium and the jacket fit well and I liked the mesh material and color (day/glow). However, after a few minutes of looking it over and wearing it, it was obvious I was going to return it. The arms has front snaps which would be a pain to deal with, and waist adjustments don't really work...but the biggest problem was the armor. Bulky...makes you look like a football player, and each elbow armor is sitting "inside" each sleeve, rather than tucked into a pocket under the vented liner. Terrible, terrible concept. When you put your arm into the sleeve, your hand runs into the elbow armor. Wearing a T-shirt results in skin being irritated by the velcro attachment points for the elbow armor also. Overall, its a poor design.