I had a V5(still in the drawer) and am using a 400 now. As mentioned above, the software has been upgraded and now does what I expect of a sat nav. Having used Tom Tom units in the past, this new unit is faster on recalculating route changes etc. , the side bar shows petrol stations and distance to same along the route. The routes can be planned as before and downloaded via usb to the 400 (been using TYRE route planner for years), there is also a micro sd port which can also be used to download / store routes.