I have not had any speed issues exporting the TW2 files or creating a project from a backup.
My biggest issue w/ that particular project, and any TW2 project for that matter, is "join" time from a client machine. Users were experiencing well over 1 hr. to join the 2+GB project, but I cannot speak to whether this was a file issue, file size issue, RAM issue, lack of 64 bit for mac, etc.