I've had this bag for a couple of years now, and I can't even count how many trips I've taken it out on, both over nighters, and multidays (up to a week). Its comfortable, durable, and packable to a point.
The bag is way bigger than it looks, and packs pretty well if you're smart about it. I've read a few reviews about over packing this sucker, and it is totally true. If you don't sacrifice some weight for the longer trips, you'll feel it in the shoulders. The shoulder straps are super thin (but insanely durable), so they do dig in if the packed weight is substantial.
There was a question about living out of this thing for multiple weeks on the JMT, and I just don't see that happening, not enjoyably at least. I've taken this thing out for a max of 5 days without resupply and that was cutting it thin. I am not a lightweight backpacker by any means, so I am speaking with bias.
Durability on this pack is fantastic. You can barely tell mine has been used, and I have bushwhacked with it, dragged it up narrow ragged chimneys, and more. Someone also asked about water-proofness; grab a rain cover with this one. It isn't very water resistant, and gets heavy when damp.
I have a pretty good quiver of bags, but anytime I go out and know I'm gone for 5 days or less, this is my go-to bag.