The construction on the Metolius Half Dome haul bag is super-bomber, from the material to the seams to the buckles. I have put a lot of big ascents on this without ever doing too much damage. You still need to line the bag with a foam pad if you are hauling on slabs, but it's not as crucial as it is with a bag made of thinner material. The river bag closure system is one of the most water-proof made. No haulbag keeps everything dry if you're in heavy rain or a mini-waterfall. However, this models does pretty well. The extra skirt also makes this a great improvised bivy sack if you need to bivy on the summit. It's easy to clip your ledge to the bottom of the bag. The carry system is about as comfortable as a haul bag can be. The inside pocket is conveniently placed.
This and the Yates are the only bags with good compression straps across the top. These are key to managing the bag when it is a bit over-stuffed.
If I had to make this bag a little better, I would make it a bit wider. That would make accessing the bottom just a little easier and add enough extra volume that the El Cap size would almost be unnecessary for any climb. Also, while I love the river bag closure, it does add extra time to open and close. I think the tradeoff is worth it, but it may annoy some people.
It is a great size for a route like Half Dome. However, it is hard to fit in everything for a Nose ascent unless you pack real light and spend two nights or less on the wall. Bring two of these on a route like Zodiac or Mescalito, and you are loving life.
The bigger version of this is the El Cap great if you only want to take one bag but hard to get to its bottom. The smaller version is the Quarter Dome which is too small for most walls but a great sidecar to your bigger haul bag or a great haul pack.
This is not one of the cheaper bags, but it probably will last longer than any bag for its price. The burly material and welded seams mean that a seam blowout is unlikely.