I've started an article on the Technet Wiki that collects usage tips and troubleshooting for Sync Framework. This can be the first place you look when you have a nagging question that isn't answered anywhere else.
Some tips already collected are recommendations about how to speed up initialization of multiple SQL Server Compact databases, how to find the list of scopes currently provisioned to a database, and how to improve the performance of large replicas for file synchronization.
It's a wiki, so you can add to it! If the answer you need isn't in the article, or if you have more to say about a tip that's already in the article, post what you know. By sharing our knowledge, we can all make Sync Framework even more useful for everyone.
Check out the article, and share your tips: http://j.mp/f1TQLi!