Olyclimber,
That's my Fav' Pack by far period! I ordered mine from Dan about three years ago after talking with him in person twice at his two stores. I demoed a larger Sarc on a forced overnighter Bivoac Seminar up Granite Mnt. and was impressed to say the least.
Anyway, I gave Dan my laundry list of do's and don'ts. I like the KISS rule when it comes to Packs so I opted for a lot of No's on mine to cut down the weight and clutter on the front.
I'm a tall guy so I figure the bag itself is about 3,100" and what I was looking for was a Blast Pack, ie., a big Daypack suitable for overnight. My term for pack it up and GO!
No bottom zipper
No daisy chains
No convertible top pocket/fanny pack
Dan informed me that 420D packcloth has the lowest water absorbtion rate of all the fabrics that he had (at that time) something to consider for here in PNW. Mine is sewn in this throughout.
With it's two detachable side/bottle pockets, two 3/4" wide stays, removeable Evazote backpad, total weight on a postal digital scale is 2Lbs, 15.4-ounces. Good enough for me.
To save even more weight you could order yours with a double layer Full Spectra (dyed gray) bottom for thee ultimate expression of bombproof durability. This 'option' costs $25.00 extra but you being a Climber might be worth it.
Dan's Packs are all the best anyway and every, single sewing point no matter what or where it is located is backed up in triplicate. Absolutely incredible the level of detail, time and superior sewing.
Packcloth I later learned from Dan is actually slightly heavier per square yard than 500D Cordura 7.4-ounces -verses- 6.8-ozs respectively. Full Spectra is a mere 3.8 ozs and Dynemma Grid also called Spectra Grid is way light at 4.0-ounces per sq. yrd.
Last month, I bought a navy blue Shovel Pocket with drawcord that is really nice. In hindsight I kinda' wish I'd got it sewn in FS. I also got a cool gray Silcoat Rain Cover that features two drawcords/locks one top/bottom and it probably weighs maybe 3-ounces if that! It'll easily cover all my gear including a 20" x 60" x 3/8" rolled Evazote pad strapped on the front with more room to spare.
Last Oct, I did a three day trip in the Alpine Lakes W' going in with 42.5Lbs and coming out carrying a sodden Marmot down bag and Tent I figure my Zero Sarc Pack weighed 50Lbs easy. It was borderline comfortable as I believe that's the maximum the three peice belt can comfortably carry. Any other brand of Pack in that size range, and I'd have been a hurtin' unit.
Oh, if you are really anal about saving weight then make sure you specify the 5/8" wide webbing for all the compression straps, mine are 3/4" which was the lightest Dan carried three years ago. Mine has 6-compresstion straps which really get this baby in tight, as little as an inch wide when partially loaded. I also have a 'stretch cord' on the front which is very usefull for securing rain clothing, wet tarp, etc.
Dan also made a custom mod' to mine recently making the top pocket detachable to where even the haul loop has this tinny velcro strip to secure it outa' the way of my head, Dan thinks of EVERYTHING on these fine Packs. Incrediable, the man is a brilliant Pack designer.
I'm also getting a Summit Flap for those times when I want to strip mine down to just stays sans pockets on smaller/shorter trips.
Simplicity to the core. Ask for a double layer, Full Spectra, 300 cu.ins. Summit Flap/Pocket. I've seen 'em and are sweet.
Mchale Packs Rock!