Ladysolly and I completed the Leigh loop. We had a lot of trouble with the first one (number 45), because I had an acute attack of the stupids, but we finished the rest without problems ... apart from lots of mud. With a few extras done, that came to 24 caches for the day. Ladysolly says she couldn't have walked any further.
We met The Two Motts along the route; they've done the Letchfield series that I'm lanning to do soon, and assured me that it's very bikable.