Just bought this a couple of weeks ago and I couldn't be happier. This is the perfect size for a long day hike, with enough room for snacks, phone, wallet, keys, some gear, and a jacket. Plenty of pockets and compartments to organize your stuff. Reservoir seems durable and it holds enough water for a whole day.
Comfortable when hiking, doesn't move around at all even when going faster. I'm 6'0, 200lbs and the L fits the bill.