Hello,
I have setup DFSR replication (just using a replication group, not namespaces), and the files in question are being being synced across a 5Mbps WAN connection. Everything seems to sync okay but when changes are made to large files I notice that the entire file seems to be transferred over again despite RDC (Remote Differential Compression) being ticked in the replication group. A large quantity of these files appear to be .PST files (using dfsrdiag). I cannot figure out why RDC wouldn't be utilized for just the changed to be copied as this would be much more efficient.
Both the local and remote server are using Server 2008 R2 and are freshly installed and updated. Both are also Domain Controllers.