In reply to Pontesford Needle: Yes, death while climbing is definetly covered.
It was interesting talking to Summit Finances because they explained the way weightings are added by different companies - often based on the experiences of their reinsurers and if they have paid out a lot to climbers in the past. Some do it purely on grade (and add premiums for Severe and up!) some do it by where you climb in the world and the altitude.
Apparently Standard Life don't add a premium for climbing in this country and occasional trips in Europe for up to 1000m.