My body's feeling it a little bit. But one good thing, my back is in good shape, and that's my main concern. I know that my legs are going to take awhile to get back to where I was a few years ago, but as long as my back is solid, I feel that I can play many years.
About the only other thing I'd want would be a wider neck. My fingers are so fat that sometimes I deaden the string next to the one I'm fretting.
Beauty is the first test: there is no permanent place in the world for ugly mathematics.