I have a B-17, broke it in with about 1,000 miles. Then put it on my 520 for a cross-country last year. I loved it until after about the 5th 100-plus day, then it was just part of the bike. Eventually, I went with a Selle SMP TRK saddle - and that seems to fit me better for long trips. Both great saddles but I like the shape and channel on the Selle better. The Brooks now sits proudly on my wife's vintage Mixte. YMMV.