GoLite Jam2

First, don't buy this unless you are truly going light. I'd say 20 pounds. This will certainly hold more, but not as comfortably and the weight will not transfer to you hips as well as a pack with a frame (even noting that this has a hipbelt). If you are very experienced you can play around with the center of gravity and the manner in which you pack, but most folks find this easier to talk about than realistically achieve.

The fabric, nylon with dyneema reinforced grid, is fairly robust and water resistant. Great for lightweight 2-3 day trips, climbs or peak bagging. Longer stuff I would recommend an internal frame pack that will carry and transfer weight much better. If you are strong enough that you don't mind carrying extra load on your shoulders (instead of the hips), then you are probably strong enough to not have to worry about every ounce of pack weight. The GoLite Pinnacle model is a bigger version of this, but makes no sense to me. If you are going to carry that much stuff then you will want a frame. Don't make the mistake of fussing about every ounce of weight and then feeling sore all over, kinda defeats the whole purpose of enjoying the trip.

I Recently went on a three day alpine climb in Yosemite. I picked up this pack needing an approach pack that would be able to be stuffed into my regular pack. This pack is sick! It is big enough for a 70 m rope, a soft shell jacket, a hydration bag, climbing shoes and power bars and snacks for my climbing partners. I used this pack all day while pulling the west arete on Mt. Conness. The features most appreaciated are the ability to compress and adjust pack, the ability to expand when the load calls for it (rope in vs in use), and the belt pouches that kept a handy supply of power bars and shot blocks while in the climb. I would recommend this pack without reservation. The only caracteristic to be aware is being so light comes at a price of durability. After being beat on over several climbs with complete disreguard there were signs of wear and tear but the dyena grid did stop any tears from running. All in all it has become an essential piece of alpine climbing gear.

I purchased the Large and Medium packs to decide which fit best. My torso is about 19 inches but I have a large chest/shoulders. I seemed to be between sizes. The perfect pack would have been the medium torso length with the shoulder straps from the large pack.

The Large was slightly more comfy overall because of the longer shoulder straps but the torso fit could be better for me. For it's intended purpose of carrying no more than 15-20 pounds, the fit is fine though so I'm keeping the Large and returning the Medium.
I'm really impressed with the overall quality of this pack.

Great frameless pack for ultralight backpacking/fastpacking. Plenty of room and very durable for being so light weight. I recommend this pack for anyone who is looking for a nice lengthy hike. If you are looking for an all around backpack to carry more than about 25 pounds, check out the Golite Pinnacle. Just finished a 4 day, 70 mile trip with nothing but praises, im officially Jammin'