Mainly- you're speaking in beefier terms than me- but I appreciate the worst case point of view in regards to abuse, and it does speak volumes to long term durability for less abused pursuits.
I build out of plain old 70d Sil. I don't strap on much more than the occasional odd item when a long resupply, libations, or luxury item comes along. In short- backpacking is my intended use- not the vehicle to pursue another sport. I'm off trail often, but not forced into wickedly devastating terrain or thorny brush crawls. There are little to no slot canyons, chimneys or ski's in my Midwestern future! Besides, us Midwestern boys are smart enough to climb the chimney first and then haul up our packs;)
I gave up on 30d because it was stupid light, hard to sew, and took too many reinforcements and fancy stitching. I can get a few hundred miles out of it- but the ounce switch to 70d was worth avoiding all the trouble.
Point being- I'd like to step up material quality now that designs are dialed in. You've done an excellent job addressing the DP fabrics. I was looking for a bit more of a UL perspective overall. VX07, VX21, or CFH50d are on my radar.
Other than a softer hand- even the 140d gridstop at $27/yd makes little sense financially- though you make an excellent point for it's use- I'd almost use a 70d sil there.
I suppose you are answering my question really- and the DP fabrics are the next step. A VX21 vs CFH50d- double weight/half cost is a pretty significant head to head. As you say- the 50d means little in that instance as a gauge.
Long story short- Seems like nobody is making that compelling argument for the Cuben I was hoping to hear. The drawbacks continue with Cuben it seems...
I was hoping that somebody would say the face fabric self heals, stabilizes the stitches, and solves the wear issues so dramatically that DP fabric is no longer worth looking at.
But seems as if that is not the case, and more and more folks like you are debunking the delam issue with DP leaving little, if anything to complain about.
VX-21 seems to be the answer for me. 6oz a yard is still a shockingly horrid weight to my UL sensibilities- but worth the waterproofness, ease of construction, etc. you point out. The VX-07 offers little advantage at $3 savings and an ounce lighter I can see.
Since you turned us on to their site- how about this stuff?http://www.cascadecraftworks.com/store/p7/X-Pac%E2%84%A2_X21_RC_54%22_Wide.html
4.4 ounces vs 6 is more my speed and not a bad hit versus the CF.
Excellent series- sorry to nitpick this item. Stepping up from sil to DP or CF is an investment in time and money I didn't want to make lightly, your timing is perfect!
I very much agree with your center stay concept, dimensions, and overall design philosophy very much. Easily one of, if not the best articles I have read on pack design overall.