I'm going to add another comment here, since we've both have known Jim for a long time. I've climbed with hundreds of partners, over the years, but after recently spending a week in Yosemite, with the senior citizen, I took in quite a display, of fine leading skills, since Jim did all the leading.
As you know, Jim likes to lead, and I was totally out of shape, and happy to just climb.
What really struck me as different, compared to almost anyone, I've ever climbed with is his ability to place pro. without hardly a pause. It seems like he is constantly moving up, and placing pro; almost as an afterthought.
I spend quite a bit, with climbers, who spend as much time pacing pro. and fiddling with their gear; as they do moving up the rock.
Jim's leading style really stands out among the crowd!