Great ventilation - Deuter Race EXP Air Pack

I really like the back ventilation on this pack! The arm straps are also ventilated in the same way with the mesh, but that is a high contact area so there is a bit less comfort overall on the shoulders because of the reduced padding. I haven't been on a ride with it for longer than an hour yet, so I can't say if it will be ok for longer rides. The bladder holds plenty of water and surprisingly seals quite well considering the closure is a fold and clip as opposed to a scr3w on with a gasket. Good quick release tube and bite valve. I'd reccomend an insulated tube cover if you are riding in the heat. Just enough storage in the pack for a light change of clothes and a packable rain jacket and a snack. The small outside pocket seemed too small at first, but it actually works fine for my phone, work badge, pen, keys, and a pack of gum without anything shifting while bouncing around on the rougher sections of my commute. Good pack.