I've been following this thread closely for a little while. Well, since my last sync failed and I've been unable sync since.
In an effort to find out the issue behind the failure I've dug into my tree. It's quite large. 47500 people, 800k records, 30k media files.
I've removed the following: 180 duplicate people, 100's media files that appear to have been downloaded up to 5 times and sometimes onto the wrong people.
I have duplications of my records which I'm just starting to go through with no clear way to troubleshoot this short of opening literally every person in my file and then every citation associated with them. I have people who have been matched up with incorrect relationships. For instance one man was downloaded again and became his own spouse.
And for some strange reason I am missing literally hundreds of my own media files in my media folder for my FTM tree.
I've spent over 36 hours so far cleaning this mess up on my Family Tree Maker file. By the time I get the records cleaned up (if that ever happens completely) I'll have spend over 80 hrs or more cleaning when I could have been researching.
But I'm feeling good, at least I'll have a file that CLEAN. Now what to do about Ancestry. The next time I sync, guess what. It will overwrite everything I've just cleaned in my FTM. I could disconnect and reupload this tree but I have 47 people invited to that mess of a tree I'm synced to. I really don't want to loose or reinvite everyone.
So here's what I'd like Ancestry and FTM to do. In the next release let the user choose which direction the sync should go. Blackberry does it. I want the ability to say take all changes from FTM and overwrite what's in Ancestry or vice versa; to only add to both trees that which is totally new, ask before deleting. That kind of thing. Quite honestly, if you only allowed a one-way sync at a time it might stop some of this nonsense. But I suspect I'd be outvoted on that. Personally, I would only sync one way at a time insuring everything came in clean that direction before going back the other way.
I'd also like to request a set of troubleshooting tools that would enable the users to pinpoint and fix the issue related to their trees without this tedious one-by-one method we are forced to do today. TELL me what's wrong. You'd get a lot less help calls.