Ok I'm a bit confused on this one. I have an '09 iMac running OSX Mavericks and also Windows 7 in a Bootcamp partition. I sync my iPhone 5s to OSX, and my wife's iPhone 5s in Windows 7. Her's syncs very fast and performs backups very fast in Win7. But my 5s syncs incredibly slow in Mavericks. I'm not sure why it is like that. Any one have a clue with iTunes would sync faster in Windows as opposed to OSX?