I have two: a High Sierra Access pack http://hssc.com/product?number=5462&lang=en (built in rain fly)

and a GoLite Lite-Speed pack http://www.golite.com/product/prodde...x?p=PA5255&s=1 (can hold 70oz bladder, but I never have used one))

The Golite cinches down to a very slim profile, but its an ultra light trekker, not a day pack, per se -- fantastic running pack, though.

The Access pack has a very well padded laptop compartment which adds to the weight and sacrifices some interior space. It has a LOT of compartments and nooks and crannies. It has fairly decent ventilation on the back, I can fit a weeks worth of clothes plus computer, phone, spare cables, whatnot. However, too many nooks and crannies get kind of frustrating and the pack and kind of on the heavy side (I paid $27 for it).

Big fan of GoLite, of course. I like the Marmot packs too. Its a toss up really. . . GoLite V024. . .slightly cheaper and almost half the weight (like it's not even there). If I didn't already have a Lite-Speed (twice as big as the V024), I'd get this.


EDIT II: Oh, I forgot to mention the waist/hip belt pockets are sizable and extremely convenient. The belt is also detachable .

EDIT III: Also, the side pockets are actually quite small. The photo makes them look bigger than they are. And theres no way they could hold normal water bottles securely. It's a 1600 cu pack.