Well first let me give you the skinny on this pack:

Features:

Quad Compression Strap Down System
Large Main Compartment with Two Zippered Organizer Pockets
Front Organizer Top Pouch with Reflective Light Loop
Vertical Storage Pocket with Dedicated Audio Port
Dedicated Zippered Reservoir Pocket on back panel
Dual Side Bottle Pockets
Comfort Padded Shoulder Straps
Soft Moisture Wicking Back Panel
Silky Slider Sternum Strap
Stow-able Waist Belt

SPECS:

Weight: 1lb, 6oz/ .62kg
Gear Storage 800 cubic inches (13L)
Reservoir 100 oz. (3L)
210D Baby Ripstop Nylon and 100D Trilobal Nylon Construction

The Good:

Size: I found the size quite pleasing. Being that I'm a 5'9" female with wider shoulders the normal packs made for females can be a bit short on the torso and too constricting in the chest region.

This bag is very roomy; you can fit a surprising amount of mountain bike essentials inside the multiple compartments. This is a good thing except be warned, your riding pals are going to be envois of your incredible storage capacity and ask you to carry their stuff too! Which brings me to my next topic....

Weight: With a dry weight of 1lb 6oz, this beauty is a very lightweight pack. Even after filling up the reservoir, packing an extra bike tube, iPod, bike tools, and a small air pump (and all the junk your friends hand off to you), I was amazed to discover the weight of the bag was still a non-issue thanks to the distribution of mass and comfortable body interface points.

Reservoir Bag: The bladder system (named the Reverible Reservior II here) uses a plastic slider closure known as the "slide seal" for the top of the unit, which makes for easier filling on account of the fact that the top is able to open completely. The bag can be turned inside out, which makes cleaning very easy, a feature I found very appealing. It is simply comforting to know you are drinking out of something you are able to clean so thoroughly.

The bite valve is also very well made! Most bite valves have a tendency to drip but this one has yet to offer an unwanted drop of liquid yet. It has a twist shutoff and an adjustable angled elbow. The quantum clip is a new system for keeping the hose from flopping around. Instead of using Velcro, it integrates magnetic clips. One clip is attached on the hose and the adjoining piece attaches to the chest-compression strap. Now you just drop the hose and it simply snaps on to the magnet with a snap. This proved extremely useful!

The Bad:

Snug Compartment: The compartment that the reservoir bag fits into can be quite snug when trying to place a full bag inside. Also the plastic clip that the bag attaches to in the compartment can be a bit trying when attaching and detaching the bag.

Multitude of Zippers: Before you wonder what in the world this entry is doing in "the bad" column, I always fear the inevitable malfunction that renders zippers (and usually whatever it is they are attached to) useless. As it stands, I love the ability to safely zip everything I decide to carry in this pack but hate the thought of a bad zipper coming between this work of art and me. However, so far so good with the zipper durability!

Conclusion:

Overall, this is beautifully constructed piece of equipment that I have no trouble recommending to both readers of my work and personal friends alike (in fact it would be nice if they got some so I wouldn't be the resident pack-mule). As MBT's RN, I continually harp upon the importance of staying properly hydrated, especially during the long summer months. This is the perfect tool to accomplish the critical task of hydration with adequate storage capacity to boot.