Right now it appears that ASPI provisions the User Profile Sync on the same server as the User Profile Application. Ideally it would be nice to be able to split off the sync onto an App Server, and leave the UPA on the front end for larger deployments, according to load distribution guidance from Microsoft.
For reference: http://www.microsoft.com/en-us/download/details.aspx?id=37000
For reference: http://www.microsoft.com/en-us/download/details.aspx?id=37000