This is versatile pack for going light and fast. It has the breathable reACTIV suspension system that is highly adjustable, shock absorbing and comfortable. It has a unique, new-fangled, dry bag roll-up style top/main closure that allows the backpack to function with or without the top lid in an innovative way. I liked this pack, but overall prefer a more traditional design like the
Black Diamond Speed 40 Backpack.
Likes
The cool shoulder strap measurement marks allow you to quickly check that your shoulder straps are even. The highly adjustable waist and shoulder straps make this a great multi-season/multi-use pack and they are easy to adjust. The straps also have elastic at the stress points to act as shock absorbers. The handy pockets on the waist belt are great for the keys and cell phone. Very useful side and back stretchy pockets allow for quick access to water bottles, extra layers or guidebooks. Plus it has a good-looking, stylish modern design.
Dislikes
The elastic on the horizontal shoulder strap connecting chest strap is on the wrong side. If the chest strap was on the side with the buckle then it could tighten up a little tighter. This is not an issue if you have an average size chest but if you are skinny then it might not tighten enough.
A more major dislike is the dry bag style roll-up top closure. This is the bag's key distinguishing feature and I didn't like it. Yes it is versatile, but it is a little disappointing when dry-bag style closures are not waterproof. I tested it under a sprinkler and it leaked. So why have a dry bag style closure that isn't on a dry bag? There must be a benefit. So I tested to see if it would close securely, and it didn't when stuffed with gear. To make the roll-up top even partially secure you have to roll it down, which decreases the storage area inside the pack. If you have the lid of the pack on, the dry-bag style closure just means you have less volume and it's harder to over-stuff the bag.
Other Versions
The traditional top loading pull-tight top style
Black Diamond Boost is very similar in most other ways except one: the suspension is different.