I upgraded to 13.10 and everything was erased. I chose the upgrade option to "keep my personal files" and I was able to find one by searching. It was a document but was not in the new documents folder. So are the files still out there?
Update, what I didn't realize at the time was that this upgrade created a new user directory in Home folder. So the the original directory for the user "Joe" was sitting beside the new home directory folder for "Joseph".
So, Joe's files were still accessible, but a new admin user was created in the process.