I first got my Gregory Whitney for a Trans-Sierra trek, over a decade later, I'm still loving it, more and more each trip. Unlike some of the other reviewers, I've never had an issue with the pack (save for 1 clip) or Gregory's customer service (clip was promptly replaced and sent to me for free).
This pack is MASSIVE, it is by no means a lightweight, super fast pack. This thing eats up gear and shows no signs of EVER being full. I've packed in a good 65+ lbs. of food, gear, and way too many luxuries into the backcountry, just because it would fit in the pack.
The compression straps on the side and bottom of the pack help to keep it snug and close to your body while still providing adequate breaking for your back.
My main critique is that the waistband took a little breaking in before it was comfortable, but if you read my other reviews, a good break in period is something I value. After a decade, and countless miles, this pack is showing no sign of stopping. Apart from a few scratches (but not tears) on the rubberized bottom, some sun and food stains, this pack is just as pretty as the day I got it.
Once you get this pack, load it up with as much gear/weight/bulk as you can and then have a friend dial in the adjustments. After that, you can start your own love story. <3