I have realised that owning 3 top spec waterproof jackets is unjustifiable and this one I never use. It's been worn five times ever and as a result it is in excellent condition - still has the factory DWR and everything. Arc'teryx no longer make this model but the closest of their current line up is the Alpha FL.
My version is the first year it was made so it has two handwarmer pockets at mid-height but uses Gore Tex Active so the jacket still comes in at 320 g. Can send photos if you are interested. Mine is the version reviewed here: http://www.backpacker.com/gear/apparel/jackets/gear-review-arc-teryx-beta-fl-hardshell-jacket/
Depends how cold it is, but I'm normally in tights and a baselayer unless it's really unpleasant, in which case I'll stick on a windproof too. I've fell run in a Powershield softshell in windy conditions and -10, though, and that was definitely needed! I've also run in a full weight belay jacket a few times when seriously fatigued and cold and wet.