Some of the other RHEL rebuilds take one or two days, while CentOS takes 2 weeks. While i can't say if they have more than a hundred users, their speed in releasing quarterly updates is commendable.
Technically CentOS is not the slowest, as Whitebox takes the wooden spoon but you get the general idea. :)
Have you thought about roasting in hell for a bit lately? If not, you really should, it's an enlightening experience.
Cheers.