We've now tested packs from Tom Bihn, Black Diamond, Mountainsmith, and Gregory. While there's no overall winner (we loved them all), we talk about the situations we'd use each pack in.
Over a four month period, we've tested these packs on countless rock climbs, a 26 mile trail on 14,110' Pikes Peak, New York City (twice), California, Nevada, Arizona, Utah road trip, London, Madrid, multiple cities in Morocco, and Rome. We definitely have the experience to talk about what we like and what we don't.
Links to reviews on each bag.
Gregory Fury 24: http://goo.gl/gNLHD
Gregory Freia 22: http://goo.gl/gNLHD
Tom Bihn Synapse: http://goo.gl/lvu3B
Tom Bihn Brain Bag: http://goo.gl/npkac
Black Diamond Dart Pack: http://goo.gl/EOWG4
Mountainsmith Colfax 25: http://goo.gl/10il4