I took this on a 3-day trip into the Grand Canyon--nothing crazy strenuous, 2 nights at Bright Angel. Down on day 1, fool around to Ribbon Falls on day 2, out on day 3. It broke on day 2.

By broke, I mean the center aluminum stay snapped about 1/3 of the way up from the base. I carried about 40 or so pounds into the canyon (adding a few on the way to help my wife's knees), and carried between 35 and 40 on the way out. The day it snapped, I was cinching the (seemingly nice) compression system down for the day trip to the falls. I imagine the problem had something to do with the hollow nature of the stay.

I did a lot of research and tried on at least a dozen packs before settling on the Z55, and, despite its weight, the suspension seemed capable, even resilient. I needed something that could handle a few days weight plus a DSLR system (camera, extra lens, tripod, etc.--nothing too fancy). Turns out it wasn't as strong as I thought.

Now I am turning to Deuter--and so far loving it.

I bought this pack a couple of weeks before my honeymoon to Glacier NP. I had gotten an Osprey as a wedding gift whose framesheet collapsed on its first trip out, and I needed something versatile. It was amazing on that trip, handling the snow and heat well. Since, I've taken it out on several day hikes all over and an overnighter in the Grand Canyon. I bought my brother-in-law one for Christmas, and he made it three days (two nights) in the Canyon with this thing stuffed to the limits. It is also very water-repellant.

The Cool Wave Plus suspension does a surprisingly good job keeping my back from becoming a stagnant sweat-pool. I'm a hot hiker, and I use to endure it with an old Marmot Eiger (which I still love and can't get rid of but--let's face it--doesn't compete anymore). Now, I still get the stability and back-hug with a lot less sweat. It won't do as good a job as the Deuter or Gregory ventilations, but balances well between ventilation and stability.

The other unique feature that I love is the seriously innovative On-the-Fly compression system. Basically, the compression straps run the length of the pack (including the edges of the shovel pocket), eventually connecting to the hipbelt and below. While it takes some getting used to when packing, I have found it to be one of the best compression systems available as it spreads the whole thing evenly over the pack. The only complaint I have are the webbing loops. They're not quite sized right, and the metal cylinder that's attached, gets pulled either too high or too low, which causes the webbing to bunch at the loops. It rarely stays in the middle and keeps thing even as designed.

And one other thing I should say--the load handling is excellent. Even with my DSLR and tripod on an overnighter (easily +35 pounds), I had no trouble. The aluminum frame rod is shaped a little more than most packs, and because I have a more muscular back and shoulders from weight-lifting, it fits me excellently (though, I did turn the rod upside down inside the pack for a better fit). Though I haven't needed to, it appears that with some careful work you can bend the rod for a custom fit.

Quibbles: (1) The OTF compression loops mentioned earlier. (2) The hipbelt pockets are small and the mesh tears easily (and also repairs easily). (3) The vertical zip pocket does not connect to the main packpag. Though, now I think I like the pocket for keeping things that need regular access but also to stay dry. (4) I noticed some issues for build quality on my bro-in-law's pack (the mesh on the backpanel was uneven, nothing you couldn't see beforehand and return).

Pros: (1) Load support. (2) OTF compression means versatility from light day hikes to overnighters and even beyond, if you know what you're doing. (3) General toughness despite being light. (4) Cool Wave suspension keeps you dry. (5) THE HEX NUT. Even though I ran out of time to talk about it, the hex nut is solid and the way MH uses it on this pack is simple and innovative. I'm surprised how little I miss buckles.

I would recommend this pack without question. I even bought my brother-in-law one when it was on sale for Christmas.