Older version = uncomfortable
Disclaimer: I own the 2010 version.
First of all, the good:
Love all of the thoughtful design features typical for an Osprey. Everything works as it should, and then some. Lots of storage, inside and out, and the mesh back panel works wonderfully for ventilation.
However, the bad part is probably the most important: comfort. The hip belt eventually digs into my hips after only 1 day of backpacking. Also, I have protruding SI joints, and the bottom of the back panel sits right on them. It is not a cushioned pad, but rather an extension of the mesh. After a day of hiking, my SI joints are rubbed raw.
It looks like Osprey has addressed these problems in their 2012 version, which is great! I'm sure the 2012 would be a 5 star pack for me.