I also have tried every trick listed here and others that are not. I have gone all the way to a complete factory restore of my iphone. It will then finish the sync as long as I don't try to sync music. Previously, it had no problem removing all my music from my phone, but wouldn't add it back. I can manipulate my iTunes library, alter metadata, etc, as normal, but when I hook up the iphone, as soon as I tick anything that causes iTunes to touch my music library, I get the beach ball of death. Any sync I try will either hang or disconnect from the device without finishing, or both. I couldn't even get one single song to download manually. I have force quit iTunes so often it makes me rant when I fill out the comments on the crash reports.
Thankfully, I suppose, I can use iTunes to sync my Air, as I have iTunes Match on so no music is synced, so I can still manage my photos ok.
Bottom line, iTunes 11/Mavericks has so far completely tanked my ability to manage music on my devices. I am at my wits end. I can usually solve issues with help from this forum. Itunes 11 is IMO the worst software update ever! None of this was a problem on iTunes 10/Mountain Lion!
It feels like those of us who want to load our "non-purchased" music, and do it outside the cloud, are no longer desirable, not important, no longer supported.
I used to eagerly await and install the latest software. Now I'm feeling totally burned and frankly disillusioned.