I’m not sure why mine are showing as being larger than your versions.
Are you sure you’re looking at the filesize for just the files that will go to disk?
OSX changed the way it reports filesizes, starting in OSX 10.6 (Snow Leopard). see: http://blog.macsales.com/1852-snow-leopard-changes-they-way-we-look-at-gigabytes-and-megabytes-and-kilobytes-as-well
so, you are probably both using different versions of OSX. This is why comparing filesizes is a bad way to check for similar files. do a sha256sum and compare output.