I'm not an Ultralight aficionado or anything but I got the SWD Long Haul 50 mostly because the X-pack material is apparently much more robust than Cuben and also waterproof. I brought it to the swedish mountains for a week this summer and experienced no problems except my color choice. Dirt is very visible on white which I should have foreseen but vanity clouded my judgement. I guess there's something to be said for the light a white one lets through, offering extra inside visibility. My buddy also got a black one so I couldn't copy him. And I was not about to buy a fucking pink or teal one.
I picked most of the extra options and strapped my tent underneath in a drybag + tent bag for extra protection.
I took the X-pack outer pocket because mesh seems fragile to me.
I packed it to the brim and lugged around 30 lbs in it without incident.
I also asked for a wider waiststrap and buckle because the default looked extremely tiny and flimsy. The guy added it for virtually no charge.
A very tiny rip (like 2-3mm) came about somehow but I dabbed a drop of McNett SeamGrip on it which seems like a permanent fix.
The guy doesn't guarantee these packs are entirely waterproof because of the seams, unless he's started using SeamGrip in the last half year, which he didn't back then. I dunno why not.
https://www.swdbackpacks.com/full-suspension-packsIf you go X-pack it doesn't quite meet your weight requirements but from what I gather about lighter materials, their cost and fragility is not worth the marginal weight gains. But again, I'm no UL-fag.
