Russ Carlson, Jr.wrote a review of Osprey Packs Kestrel 38 Backpack - 2197-2319cu in on September 5, 2013
Familiarity: I've used it once or twice and have initial impressions
The positives: the overall size (M/L with 2300 cu in) is very desireable. The overall fit was good. Adjustable torso a plus.
The negatives: the hip belt is too flimsy and doesn't transfer the weight to hips. A 2 L water bladder pushed against my back, and not being a suspended-style, was uncomfortable and hot. No side access to main compartment.
I did exchange for the Osprey Stratos 36L (L) which I think is a far better choice for me. I am 6 ft tall, 214 lbs, 36 waist, 19.5 in torso.