We have recently changed out Windows 2012 R2 replication structure from the default mesh topology to a hub-spoke set as we have taken on more organizations. The hub consist of one of DC's with all FSMO roles another another one as backup. Another site has all other DC's which are onsite. We have notice that AD changes are slowly to replicate then they used to be and believe this is because the replicatin interval is set at 15 minutes. Is there any harm in reducing this to 5 or less? Any other recommendations are welcome.