First off, this pack is epically lightweight considering all of the features it is stocked with. It is a little bit flimsy, after a years worth of use I have broken a compression strap and worn through the fabric around the frame in one spot. That said, it is still pretty durable considering the weight.
I have had it in light rain for 2 hours before the inside started to soak (it was a little wet though)
This pack is more suited to general backpacking than specialized applications because it fits very wide. I can fit my kelty lightyear 0 degree down sleeping bag horizontally in the bottom of the pack.
It is fully loaded with every feature under the sun: gear loop, ice tool loops, hip pockets, shoulder pockets, multiple top pockets, compression options, etc. Not only that, but it swallows EVERYTHING. I take it on multi day trips in CO winter and it works great with my fast and light style.
Overall, VERY COMFORTABLE and very practical: its my go-to pack for multi-day adventure.