I've had this pack for about six months now and it has been all over Virgina: Shenendoah National park to MT. Rogers National Recreational Area and many cool places inbetween. 100 LT seems to last about 15 miles. I was worried about the size when i first recieved it, but you can really load this pack up. I use it for hicking, biking, and trail running and i've had zero problems. Now I live in Texas and it's getting ready for a Big Bend Adventure. Add some ice to your water and enjoy! Also great for outdoor concert festivals like Austin City Limits. Bottom line: great pack at a good price.

So I had been looking at getting a hydration backpack for a while, but I didn't really need one and since nicer ones set you back at least like $70 or so, I waited. I lucked out and saw the Hammerhead on the site, so I figured that was a good deal. I also have a The North Face Neutron backpack that I use day to day and I like it a lot.
I run trails, usually once a week, but most of the time I just use a hand-held water bottle because I can fill up at a few drinking fountains, and most of the time my runs are around 10 miles, so more storage and fluid isn't totally necessary.
My running crew and I, however, planned a solid 20 miler, so I figured this was a good time to finally try out the hammerhead. I filled the bladder up about 2/3 of the way to keep the weight down some, and loaded up with some snacks for all of us.
All in all, the pack did great. I had an issue with the hydration hose coming loose from the bladder, but only once, and otherwise having my hands free and my water readily available was nice. The pack held every thing with lots of room to spare, which is nice, although for a run I could probably do with something smaller. The pack sat really well on my back and didn't bounce around at all. My back got sweaty, sure, but it wasn't terrible.

The North Face Hammerhead backpack is the perfect bag for hiking, bike riding, or camping. It is large enough to hold all of the essentials, yet small enough to be a convenient pack to carry. The straps allow for plenty of room to adjust the size of the pick so that it can hold larger items.

the pack is great, it holds plenty of water, the ventilation system helps keep your back dry. it is a bit small, so dont plan on packing more than what you need for a day hike, but i dont consider it a drawback, it is nice because of the compact size of the pack