My Millet Expedition 65 has yet to let me down. I've used it on week+ trips, ski mountaineering, day climbs, and more.
Light - 1560g, but not ridiculously light, so it's still durable
Highly adjustable - volume can be adjusted from ~30L to over 65L (w/ compression straps and an extendable skirt)
Water resistant (proof?) - materials readily repel water, a pack cover is not needed on most trips (unless major storms are forecast, then I bring it)
Extras - Secure ice ax attachments, gear loop on waistbelt, vertical zipper on main compartment for easy access, can easily carry skis (a-frame)
All in all, a one quiver pack in my book.