Scheduling Fluid Class Search Incremental Builds

We currently have the Incremental Build for the Class Index Manager process scheduled to run nightly. We have been asked to increase the frequency, especially during periods of frequent updates to class data. I am interested to hear what frequency is recommended or has worked well for others. It looks like our servers are capable of running it hourly, but are there other concerns to consider? For example, if it runs hourly during the daytime, what happens if an administrative user is modifying a class record at the same time the incremental build runs?

Thanks for any thoughts.