In reply to Dispater:
> Not sure if it's a lack of focus when not on the sharp end, or if they were just coincidentally tough routes at their grades.
For me, it's a lack of focus. Often when I second a route I find myself thinking that I'm glad I'm not leading it, and wouldn't it be scary on the sharp end. On lead I'm utterly absorbed by the intricacies of climbing, managing the pump and ensuring that I'm safe, and consequently climb a lot better.
I can see why some people are happy to just second and don't feel any need to lead but I couldn't imagine ever feeling like that myself. Yeah, it's good to do stuff that's harder than I would usually climb and to have a break on multipitches but I'd almost always rather be leading. I just get so much more satisfaction out of it and I think I'd have gotten bored of climbing if I just followed my partner up stuff!