I don't. They were bought in 1983 specifically for racing XC in the Gruenewald in Berlin (little stipply sole). Also good on sand and snow.
The original sole started to peel away at mile 23 in the Blubberhouses 25 a couple of years ago. This caused me to slow down so much that Jez nearly caught up with me (but not quite, ha!).
Lovely sunny day in Jockland. Good luck to all 3P'ers.