In reply to west-country-wanderer:
not sure how light you want to go, but if you do check out the arcteryx cierzo.
bloody light, nothing extraneous, axe loops, places for clipping stuff, 35L and heres the amazing bit - affordable ($100).
i got one recently and have given it a few decent hammerings on overnights, carting ice gear.
for something so lightweight it feels solid.