There is an open-source librsync implementation for Windows. And much of Unix systems do have rsync installed and accessed via a simple SCP call. So – it would be great if WinSCP will support rsync protocol in the future.
In my practice, rsync is VERY fast – it synchronizes two 50M directories in about 10 s, when there are no changes in them, and there are about 1000 different files. Ping time is not so critical in this case as it is in WinSCP (600 files with ping = 500 ms are synced about 10 minutes minimum). I think that rsync is the fastest synchronyzation solution, but it has 3 minuses which WinSCP could destroy after the integration:
- complex command-line interface
- no support for keepuptodate feature
- no builtin support for persistent SSH connections