i have used mapinstall for a good while, its good and does its job, express on the otherhand has always seemed to be a little problematic (not for me, but others), and with it being the software most will have to use to update their device, this does not help, but if you can at least use express to get your maps onto the pc or mac, mapinstall should do the rest. Ideal if you want to download all the maps and install at a later date, or you have no sd card handy at the time of your download but still want to download the whole map set.