I compared the Khamsin and Nozone in the shop a few years back and chose the Nozone for the frame reason that Cracked pointed out - good alpine/crag pack and pretty bomber. The Khamsin frame also jabbed me in the back of the head when I did the 'look up' test.
As far as Ospreys- I have an older Xenith (friggin huge) that I bought from Swallow's nest. I haven't had reason to carry it for a few years, but the thing is built well, and has a good suspention - especially if one is to fill its 7,000 inch space. One cool thing about Osprey - they don't advertise much, and most of their sales are through shops and word of mouth.