REI generally does yeoman's work with their packs. The Flash 65 is a solid, lightweight pack with plenty of features. We tested the women's model, which has contoured shoulder straps and waist belt and weighed in at just under 3lb for the small. The pack is available in small, medium and large sizes, and the top lid, framesheet and stays are removable to get down towards a 2lb ultralight setup.
The Flash 65 is a 65L/4,000ci capacity top loader and comes well appointed. The main compartment is very hydration friendly, with a bladder sleeve, hanging loop, dual clip hooks and exit ports for the tube on both sides. Other storage includes a spacious shovel pocket with a waterproof-zippered stash pocket on the outside, a top lid with a velcro map pocket underneath, two nested mesh pockets on each side, and a zippered camera-size mesh pocket on the right front waist belt.
Attachment points abound, including dual ice axe loops, tie-downs on the top lid, a compression strap for a rope or whatever on the top of the main compartment and straps on the bottom for a pad or tent. The pack carries quite comfortably, and adjusts well with one exception: the lumbar strap is too low and will squish your breasts like a salaryman copping a feel on the Tokyo subway. With a little creativity this can be altered, however, and you're left with a comfy, feature-rich, inexpensive and lightweight pack that will serve you well on multiday trips.