This pack is great for carrying up to about 40 pounds. Over that I want more support. But this thing is LIGHT! I have used it for a great pack rafting trip down the Colorado River. We put in at Spanish Bottom after hiking from Elephant Hill, carrying our boats, life jacket, paddle, sleeping bag, pad, cloths, helmet, stove, pot, food and other odds and ends in and on (paddle) this pack. It carried well and does not add 5 to 10 pounds to the load like most other packs. It is simple but has good necessities...two compression straps on either side that are long enough to hold a tent or pad (or paddles) on the outside of the pack, pockets to catch poles or tent on outside of pack, large water-proof zipper pocket that is easy to access, even when full, by being on the back middle of the pack. After unloading all the gear and going for a hike, it was easy to compress the straps and head out with this light weight pack. It has been through some serious use and is still holding up well. I have also used this pack guiding in the Tetons and climbing the Black Ice Couloir recently. Light is truly right and this pack proves it.

The GoLite Pinnacle Pack is what it is. It is an ultralight backpack for people who actually practice ultralight principals. If you have a "normal" size tent and sleeping bag, find something else as this won't fit. I found the 4,500 cu/in size a little optomistic and the long version wasn't as long as other packs I've tried. It is made well, but it has no frills and doesn't appear willing to take a terrible amount of pounding - then again, how often do any of us really sling around a backpack instead of treating it as if we had the world on our back? The top cinches tight, so plan on figuring out ways to keep the contents dry if it rains.

I am a gram-counting ultra lighter but my g/f is fairly new to ultra-lighting. I have been trimming away her pack weight trip by trip and this time it was with a new pack. She has gotten her gear solidly in the light weight realm. I estimate her base weight at about 10-14 lbs plus 10-15 lbs for food and water on our trip with this pack.
She seemed very happy with this pack. It was a bit heavy on the first day with a full load a food and water but after that I never heard a complaint. It is a pity they don't make women's in large as she is rather tall but overall it fit her frame well so I suppose it was not an issue.
The pack suits her quite well letting her bring the extra changes of clothes she likes. I my option this pack is massive for an ultralight pack but traditional backpackers will have some hard choices to make.
The things I didn't like about this otherwise excellent pack were
1) The cinch straps we longer than I would like. This allows them to slap the pack a lot and get caught up in things.
2) The pack features a nice outside pocket. I found when the pack was full and being worn it was hard to operate the zipper. Not a big deal but it made it hard for me to fetch things for her on the first couple days as she had to take off the bag to let me close the pocket.
The things I liked
1) A great feature is as her load got smaller that pack features an awesome set of volume adjusters to really shrink the load.
2) Another feature is the pack has a very nice back-pad built which my g/f could use under her feet at night reducing the size of the sleeping pad she carried.
3) It looks like it wears like iron. We only used it thus far for 6 days but in those day it was dragged across enough sharp rock that it would make most of my other packs weep.
I recommend this for someone between heavy weight and ultralight or winter ultralight.

I purchased this bag after much research. I found the bag to be extremely light for the size of the bag. It is made of a very durable material. I torn through the woods occasionally snagging on a branch and whatnot and I did not have to even look back, no damage at all. There is little to no frills to the bag (as in pockets, etc) but it is great for people that want to get lighter on their now 5-9 pound packs. Remember: If there is no room for it, you may actually leave something you will not use at home. I think that out of all the Golite products I have purchased, this is by far the best of everything. Enjoy the woodds and keep it clean.

super lightweight
snug fit
lots of room, one just needs to arrange their pack wisely
weatherproof