1:06 p.m. on August 18, 2010 (EDT)
In my mind, the biggest difference between the Pinnacle and the Vapor Trail is comfort. For me, the Vapor Trail brings the plushy comfort of a heavy internal frame pack to the world of ultralight. That sounds like marketing hype, but in the case of the VT it's true- the hipbelt and shoulder straps foam backpanel all were borrowed from their heavier packs. Instead of giving the VT thin shoulder straps, they cut weight out of the frame and packbag.
I'm probably a bit of an outlier, but the Vapor Trail fits me *way* better than the GoLite Pinnacle. The belt and frame transfers weight to my hips better and the shoulder harness works well for me. The GoLite Pinnacle/Jam/Peak's shoulder straps all angle in when tightened up, making more of the weight carry on the inner edge of the thinner shoulder straps and digging into my shoulders. This is made worse by the fact that the belt doesn't do much weight transfer to my hips.
For frames:
- The Vapor Trail uses a thin HDPE framesheet and a thick high density foam backpanel. Both are part of the pack, and not removable. Shoulder straps are sewn in, torso is not adjustable, but the hip belt can be swapped out for other sizes.
- The Pinnacle uses a thin foam pad for the frame. The packbag itself is cut in a way that the pack has somewhat of an S-curve shape. If you pack the bag carefully, this can be very useful for getting some weight transfer to your hips. Framesheet pad is removable. Shoulder straps and hipbelt are sewn in, torso is not adjustable.
Advantages of the GoLite Pinnacle:
1. 13 L more volume
2. Ventilated mesh backpanel
3. Tougher Dyeema fabric
4. Zippered pouch in the front of the pack
GoLite has a reputation for having pretty accurate claimed weights. The reason you've seen the GoLite Pinnacle's weight as being anywhere between 1 lb 8 oz and 2 lb 4 oz is that they've had a few revisions of the packs in the Jam line and they sell different sizes of the pack. The current version of the GoLite Pinnacle in size Large weighs 2 lb 4 oz; the medium weighs 2 lb 1 oz. The Pinnacle/Jam/Peak packs have been getting heavier over the last few years.
Granite Gear, on the other hand, usually claims one or two oz less than the actual weight as shipped.
I've never owned the GoLite Pinnacle, but I do own and use a GoLite Peak (2010) as my daypack and I've tried the Jam and Pinnacle on 3 mile trial hikes. I have owned a Vapor Trail as well as the Nimbus Meridian. I really like the GoLite Jam and Peak as a daypack.
As it always is with packs, the best thing to do is to try both packs and see which one fits the best. All of the pros and cons put forth by people like myself will amount to nothing if one of them is clearly more comfortable than the other for you. If you don't have any shops locally, you can always order both from REI or Backcountry, try them out around the house or take a walk around the block, and return the one that you didn't like as much.
Good luck picking a pack! :)
Aaron