The only caveat to using rsync is that I've found it to be quite chatty, so if you're running it over a low bandwidth or high latency connection, you may find you're better off using vanilla FTP (which seems to be better behaved on those kinds of connections). It seems a bit counter intuitive that a "dumb" protocol such as FTP can be more performant in some cases, but I guess calculating which blocks have changed is an (I/O and network) expensive operation.
Cheers,
Peter