In reply to llanberis36:
Hey,
I've used the Alpha Lightweight. It's a nice jacket, pretty bombproof, but a little over kill for alpine summer. Most of the time this jacket lives in my bag, occasionally coming out on a windy summit or if the weather comes in.
Typically, for that activity, I use a lighter/much cheaper running jacket in a size up that what I'd usually buy. Something simple with a chest pocket is ideal.
I've currently got a Patagonia Storm Racer, which works great.
I used the Alpkit Gravitas a load previously - and it was also ideal.
If you want something climbing focused, but a little heavier. The Patagonia M10 is great, and has an excellent cut.
Hope this helps.