Gregory. Packs. Same thing. Gregory has been synonymous with backpacking since before back pain was invented. Not that you'll have to worry about that with their packs, which consistently carry like a dream. For alpine loads up to about 40 pounds, the Alpinisto 35 (as in liters capacity) is your weapon of choice.
The Alpinisto 35 (also available in a 50L) is an excellent mountaineering pack that stows all the essentials for a heavy day or light weekend of technical vertical fun. Leashless-compatible tool sleeves, ski loops for A-frame carry, hypalon crampon panel, and dual gear loops on both sides of the waist belt round out a serious-alpinist feature set. The build says serious too; it's made for the kind of knuckle-dragging abuse typical of the underfed and overstimulated climber set. Hoo-ah!
Gregory's Wraptor stabilizing system has two points of contact for the webbing that connects the pack bag to the shoulder straps. Combined with the wide belt, ample compression points and helmet-contoured floating top pocket the Alpinisto is a stable load carrier. Stuff it past its 35lb rating and it still doesn't complain, thanks to the removable aluminum stay and HDPE framesheet. The Alpinisto 35 in a medium tips the scales at a very reasonable 3lb 14oz. Minus the framesheet (9oz) and belt (5oz) you've got a 3lb burly climbing pack with a minimalist hip belt that should nest nicely with your climbing harness. A great pack for vertical all-season adventures.