Osprey are known for making good packs, and they haven't disappointed with the Mira. The 18 is a small pack, but it's possible to take everything you need for a day in the mountains with unpredictable weather. The integrated rain cover is fantastic, as is the hydration system. The bladder is quite rigid and its compartment does bulge into the main compartment, but the comfort and ease of use on the go can't be faulted. Multiple small features - like the magnetic bite valve attachment on the sternum strap and the electronics pocket - make this pack a joy to use. Might be nice to have pouches on the sides for extra water (eg. for the dogs), but would make the pack heavier. As it is it has a nice narrow profile on the back and doesn't hinder movement. All in all: Fantastic pack! I think it's a winner and I won't be leaving it behind on any adventures.