Todd Geist has put together a great video showing how imports will let you down when you’re syncing records. Tricky stuff, but the basics are very well explained in this video. (Import failing begins at 11:40)
Todd’s article/video also includes a pretty cool demo file for showing how the sync / import works. It’s not fully fleshed out (i.e. it’s a demo) but it’s unlocked and has got a really nice FM13 interface. (July 2, 2014 – this file is now the example file for GoZync 5.)
GoZync uses transactions to sync… this is why.
Todd’s series on transactions is also highly recommended.