I have a set of Williams System 30s, Williams System 50s (no longer advertised by Williams) and DT Swiss 1250s; all three wheel sets have great ceramic bearings. You would expect that from the 190 DT Swiss hubs. But, the Williams ceramic hubs roll very well. I plan to get a set of the Williams System 19 for my single speed bike. I don't think you would be disapointed with the Williams wheels or the service. You do know that they have a new carbon set of climbing wheels for just 999.00.