We have a project where we operate a central Revit Server 2013 Host and different companies participating in the project have their own Revit Server 2013 Accelerators. After the project has gone from Revit 2012 to Revit 2013, we have received feedback that sync with the server has been noticeably slower. The reason that we wanted to go to 2013 was to get rid of some instability with the 2012 version, and then being able to lock models and that this should be improved in 2013 - unfortunately now with other, more extensive problems. What we have asked for confirmation is that the local accelerators have installed the rsn.ini which we have distributed to key personnel (responsible for local servers). In addition, we have asked some users try to remove the checkmark in "Save local file before and after syncronizing with central" in "Syncronize with central" dialog.
We have found that the "Support Files" on models in general are very large (well up to 100MB and often many times more than this). The same models in Revit 2012 had support files barely enough came up to 1MB.
Another symptom we have seen in 2013 is that the Revit Server Admin (web interface) responds instantly and as expected the "Host", but the different "Accelerator" 's takes a very long time to generate the folder structure and open the different folders to view content.
We have given them all the documentation tips and tricks from Autodesk wiki hoping this could help them out... But not so far.
Sorry to read that you are having an issue with the 2013 version of Revit Server. Have you contacted and raised the issue through a product support channel? I'm sure they will be happy to assist you and work with you if there is any thing we can do to improve the performance.
If you have already tried contacting the product support team. But you did not get response or did not get satisfactory answer, then let us know of your contact e-mail address. We will try to see if we can find somebody who can assist you.
Also, a kind reminder that this is an Revit API forum; i.e., discussions about programming using Revit .NET or Revit Server REST APIs. People who are watching this forum may not always be an expert of product side of issues. Product forum is more appropriate for questions about product itself. Product supports team has more experience with the product.