I have had one for two and a half years and used it for around a dozen 4-5 day mountain trips, mostly in winter. At 3lbs too heavy to be considered ultra-light, but not that heavy for a very comfortable, rugged, large capacity pack. When I was younger I loved my Dana Designs Terraplane; now I love my Quest. Got it on sale.
My BPL review: http://www.backpackinglight.com/cgi-bin/backpackinglight/reviews/display_reviews?forum_thread_id=41003&cat=Backpacks%20-%20Internal%20Frame&cid=14