I have had the same bike since new. It now has 52,000 miles on it. I'm on my 4th set of cam shoes. Opened it up at 20,000 and original set was completely shot. Put in 3rd set at 30,000 - slightly worn but I was upgrading to a new cam so I replaced them. At 50,000 replace outer shoe only. Inner shoe was fine. I know others who didn't show much wear at 40,000 miles though. It just depends on the tolerance build up in the parts. If loose they tend to wear quicker.
The only other problem I've had is the jack shaft primary seal. I'm on the third seal. Again, I know other guys who have 50k+ miles and have never had a seal problem.
Overall, it's been a great bike.. Hope to put on several thousand more miles before retiring it.
$troker