I found an answer Here for a problem I was having regarding transfer speed. It says that the problem is rsync's delta copy was downloading files twice, once for checksum and once for actual transfer. The solution provided (DeltaCopy server) worked, but I'm not certain the reasoning was sound.
The man page for rsync, the -W option says that it is enabled by default for a local to local copy. It also says that a Whole File transfer disables the delta transfer.
a: is a transfer between a local directory and a mounted share counted as a local or a remote transfer?
b: if it is counted as a local transfer, why was I getting 2 MB/s speeds between local/mounted share and then 10 MB/s speeds when I started using a DeltaCopy server?