I have a related "question" and there are two other recent threads regarding Naviextras pertaining to my question, so I'm going to post here because this thread is most likely to come up in future searches. For reference, the other two threads are:
http://avic411.com/index.php?/topic/80463-how-do-we-back-up-our-map-locations/
http://avic411.com/index.php?/topic/80503-am-i-missing-something-how-exactly-do-i-update-gps-maps/
An earlier post to this thread brought up the one free update we get... but stated the update is through AVICSYNC (if and when that comes about). However, I don't recall any authoritative documentation, advertisement, or such stating that one free update would be supplied through AVICSYNC.
Now I'm wondering if that free update is furnished through Naviextras, and I'll explain why...
Went though sync procedure on HU end and got to computer stage. Before opening Toolbox, I made a copy of the synctool folder placed on my USB to my computer for later comparison. Opened Toolbox, logged in, and stick was recognized. Home page proceeded to list a few available updates(?) on left and an update(?) on right for USA and Canada for $129. I'm not going to purchase an update at this point in time so I went to the Updates page, which said there's one available update: Map of USA and Canada. So I clicked on the Install button. App proceeded to do seemingly lengthy download of many files.
After download complete I got a message the update was installed. At this point I decide to do a before and after file comparison. The directory structure appeared relatively the same. I didn't compare the entire directory, but I did notice there was some files and a folder added to the "license" subfolder...

Selected items were added. Note the year and quarter in the file names. So now I'm thinking this is the one free update... and I don't want to "commit" at this point in time if I can delay to a future update. So I decided to copy stick contents to computer and restore from pre-update copy. Initial attempt to copy updated contents failed on one file that I'm aware of, and that is the last in the picture, because the file name made path too long. I managed to copy it to another directory with a shorter path. However, when I tried to restore the pre-update copy back onto my stick, my computer failed to copy that file for the same reason. I did not attempt to put in a directory with shorter path. Instead I decided to clear the entire stick and see if the HU would repeat the original sync process. It did and comparison with first copy appeared to be the same AFAICT without an exhaustive comparison.
So back to computer and repeat process (FWIW, I closed Toolbox in between). Everything same as previous session. Decided not to update map this time. My purpose for doing this is to install custom POI's as a backup for saved locations. There have been reports the HU sometimes wipes saved locations from internal memory, and I have also noticed firmware update instructions state navigation is reset to default, so I have to assume saved locations are also wiped on firmware updates.
So this go-round, I viewed Updates page, same as before, but do not follow through. Went to Extras page, loaded my .kml file, and follow through to acknowledgement (don't recall exact message wording). Again I compare stick with original copy. Related folder and files were added (we can get into that later). I then I compared the license folder. It was the same as when I did the map update (as in attached picture).
So now I'm thinking any change through Toolbox will permanently lock in the year and quarter of the free update. Until I get some confirmation from other users whether or not this is the case, I am not following through on the HU end...