I’ve put hundreds of miles on this handheld, and a couple falls. It is so comfortable in the hand. Super easy to adjust or swap hands. I’ve shoved an entire tshirt in the pocket, but usually use it as an empty gel receptacle. It also makes a great cushion during a fall! The bottle it comes with is good, it does struggle to wiggle back into the sleeve sometimes after being refilled, but it carries such a variety of bottles it hardly matters, if it annoys you, swap bottles. I’ve done two fifty milers with it and haven't experienced any arm fatigue, the “spine” encourages a very relaxed grip, and the cinching system handles all the squeeze. Very very good. Probably my most used piece of running gear.