My first and only time out with this pack so far has been on a trip through the Needles, and surrounding Canyon lands National Park, in Southern Utah.
Water wasn't an issue except having enough of it with you, as none is available there currently. So the only testament to the water proof that I have is the bathtub and the hose which I feel to be every bit as good as real world short of crossing a river with it. Even loaded it wasn't an issue to keep the weatherproof pockets out of the water and the rest in. It's a very great design and works very well.
Loading is easy and there are enough external pockets for quick access. It did get to be a bit of a pain opening the drybag top to switch layers. The front pocket could hold some light layers but not rain gear. A small price for ensuring that your important gear is dry though.
It held up very well. Through the narrows and shrubs I found myself cringing as my pack scraped or as I was stabbed by a tough branch. I was pleasantly surprised at the durability of the pack though as there were no rips, holes, or even visible abrasions to the material. I wasn't sure either with the zippers as I forced the seams shut over my gear in the pockets but they too seemed to cause no abnormal side effects.
As far as the comfort factor goes it distributed the weight very well. All of the straps are comfortable and very adjustable. The disc system made for very smooth movements whether it was a looser fit or strapped tight to your body for more challenging navigation. The pack was just not a burden/limit short of the extra weight.
Also, they recommend the bigger pack for week long trips. I had everything that I could have imagined wanting/needing and it would have been sufficient for a week long trek. ESPECIALLY not having to pack in 6 liters of water I could imagine room for even more and less weight.
My only complaint or biggest that I can think of is poor hydration compatibility, as with most all packs that I've came across.

These are expensive but as anyone on a long trek or a simple day hike has come to learn very quickly, you can't put a price on protecting your feet. There are short term pricey options such as moleskin, and perhaps still necessary for the very sensitive, though I doubt it. These socks provided excellent support, cushioning, air-flow, shielding. I had no issues with sweat, abrasion/rubbing, odor (at all), etc.
they utilize nearly pure silver in the footbed portion of the sock. I'm not sure what that helps with but it didn't restrict the fabric in any way.
I bought two pairs and will be watching for any deals to buy some for everyday life. I personally have a problem with odor, air flow, and fatigue. With these socks either hiking 8 miles with a pack or sitting at my desk at work there is NO PROBLEM.

These socks are worth thier weight in gold.