When speed and miles are needed, a new Zimmer-Built ZB2 style roll top w/twin daisy chain and (removable) hydration sleeve holder inside — totals 18 oz (21" torso height). Frameless but I use a folded 3/4 Thermarest inside, plus a sit pad that doubles as a virtual frame and triples to keep my feet insulated at night. Nothing really extra but built tough as to minimize snags on branches, thorns, and spines.
Daisy chains and twin top straps give it a little more cargo capacity for an oz or 2 penalty. Plus I like the look of plain Dyneema.
