Heya,
I know a lot of people use the specific running packs from OMM, having looked at them, I decided to go for the Jirishanca 35 as I wanted something a little more akin to a Mountain 35L which could double as a running 35L.

Its pretty damn good, and a good compromise if you only want 1 bag to do both things and aren't looking for the lightest of the light. You could use it for a Mountain Marathon, and equally use it for a scrambling/climbing holiday or a ski/board holiday as well.
Have a quick butchers if you're interested.

http://testedtodestruction.blogspot....anca-35rl.html