I hear you!! My large tree (7600 people) synced OK right after the latest patch. It has failed all *5* times that I have tried since then. I compact my tree every time before I try to sync.
I have filed another bug report with Customer support and sent the Sync Reporter files from two of the failures. Each file is 8+ MB in size, so had to send 3 separate emails to get the reporter zip files plus detailed tracking of what I had done. They all fail just about the end of the process as it is starting to update the database.
I was quite disappointed, since that tree had been working OK for a while now.