I have over 6k miles on rim brake Enve SES 3.4 wheels that came with my road bike, that I bought used. Not sure how many miles the previous owner had, but he was an active racer, so probably quite a few. For me, the biggest limiting factor is that I can't use tires larger than 26mm due to brake arch clearance.
__________________
"Swedish fish. They're protein shaped." - livedarklions