Rating: 5 / 5
The Golite Pinnacle is the larger, but apparently similar, sibling to the Jam2. I have now taken my new size L Pinnacle on three 3-day trips and several shorter ones, and can share my impressions. I have not weighed it full, but it has held 60m of 8mm rope, harness and glacier gear, picket, light ice ax & crampons & helmet, tiny tent, and clothing for summer Cascades at altitude, as well as the usual light gear and food. I found it comfortable with this load. The hipbelt 'wings' have some padding and a slight cup for the hip. The shoulder straps are reasonably padded. The lifter straps don't work quite as well as on a frame pack, but they do serve to vary the feel a bit as you go and to prevent the top of the pack from sagging over. The back panel has thin padding. Assuming you're not carrying rocks or a giant water bladder inside, a frame would not add anything to a pack of this volume. It holds its shape well when filled. As with other frameless packs, the more it is loaded, the stiffer the pack gets. The volume reducing system at the bottom (see BPL's review) works to some degree, but with light loads it nonetheless becomes more flaccid. Ideally you'd use a smaller, full pack instead.
The side mesh pockets allow for easy reach of water bottles. I holster a 1L collapsible Platypus upside-down in each pocket so as not to catch on the mesh going in. The Pinnacle has an internal pocket for a bladder with drinking tube, but it has the usual problems with refilling when the pack is tightly loaded. The rear pocket, which has no bellows or gusset, is a bit tight and thin when the main compartment is full. The roll-top works fine. The generous compression straps allow for strapping things to the sides.
My biggest concern is durability, and I'd give it a 4.5 due to that. The Dyneema fabric is adequate, but threads are visibly straining at several seams when this 4650 in3 (76L) baby is full. This is noticeable along the vertical seam at the edge of the backpad, around the top shoulder strap attachment points, and where the roll-top strap is attached. The seam opening is ever so slight and not about to fail soon. Nonetheless, perhaps six additional ounces of reinforcement plates could be justified. Even if raised from 1 lbs 10 oz (size L) to 2 lbs, it would still have an excellent volume to weight ratio and a comfortable ride.
The Pinnacle admirably serves for several days with light technical gear, for winter overnights, a week of warm-weather ultralight backpacking, or carrying gear for two. It offers significant weight savings over the 3-5 lbs large climbing packs that usually fill this role, at perhaps the cost of a slight decrease in longevity. It is now my most-used pack.