I purchased a new Trek 5200 (9 sp) a few years ago and had the dealer upgrade the B/B and crank to Dura Ace. After 6,500 miles the B/B started "clacking" away and I pulled it only to find one of the needle bearings was missing. So I replaced the bearing cups. Now, after another 6,500 miles I find the whole B/B is worn out. I have heard of other complaints about Dura Ace B/B's coming loose or wearing out quickly. It seems to me these things ought to last more than 13,000 miles.
I am curious how many other people have experienced this. Also, the Campy Record seems to have much smoother bearings. But I wonder if they last longer?