The convenience of external fill in a sleek bike pack. The 2L Antidote reservoir can be refilled on the fly via the quick-release flap on the front of the pack. Two external pockets for small items like keys, wallet, phone or storage for a shed layer. Stretch elastic side panels provide for expansion; twin compression straps shrink pack down when empty. Reflective back strip with tab to click on a blinker for early morning and evening safety.
I have had this pack since last fall and have used it in a variety of conditions. Overall, it serves it purpose extremely well. Because it has little storage I mostly use it for half day or less rides/runs. In these situations, it carries enough water for me and my dog--with enough room for wallet/phone/clif bar in one pocket and folding dog bowl/snacks in the other. My one niggling complaint is that (especially when trail running) I can not get it adjusted quite right. No matter how much I fiddle, the outer sides of my chest/armpits always end up a bit bruised. I am not an abnormal sized guy--6'2 200lbs. but for whatever reason the straps just hit in a weird spot--this is not the case with the bigger blowfish.