I have a Garmin Touring, and every time Garmin Express tells me that there is a map update available, it's about a 5.1Gb download to get the updated maps onto the device. Is it not possible to utilise something like diff files, so that only the changes rather than the complete map set has to be downloaded each time. This is about the third or fourth time that I've had to do the 5Gb download for map updates.
