Well, I just completed the update process, which probably took around 3.5 hours, in all! Left with a bit of a mystery, in that the new data is 12.7GB, versus 14.7GB for the old data. Not sure why that should be - usual experience is that data increases at updates, but hey.
Checked the updated SD card in the car and it accepted it without any delay and displayed the usual map screen correctly. Tried putting in a route from my destinations, which are all there, and everything seemed to work as it should. Not tried driving a route yet, but can't see any reason for concern.
So, as to whether it's worth investing 3.5 hours of your life in this update, I can't yet help, but the last update I did, which was November last year on an MIB 1, replaced one verbal error with another, on the same road! I was hoping that this update would get rid of the bit where she inserts an unnecessary "street" into directions, as in "turn right into "street" Wisteria Avenue", but, as said, yet to drive a route.
