If you're regularly syncing from an older version to a new version, you can likely optimize further using gzip with "--rsyncable" option. It will reduce the compression by ~1% but make it so differences from one version to the next are localized instead of cascading through the full length of the compression output.

Another alternative is to skip compression of the dump output, let rsync calculate the differences from an previous uncompressed dump to the current dump, then have rsync compress the change sets it sends over the network. (rsync -z)