And the same things I liked about the RoadMate 1215 are still present and correct. It's extremely easy to use: tap the Menu button and you're simply presented with three big buttons for showing the map, entering an address and searching for POIs, with a further three small tappable shortcut icons beneath for quick routing to your home address, bringing up a list of nearby garages, and accessing the Bluetooth hands-free settings.
Address entry is generally straightforward, and I like the way the Magellan sat-navs split the screen in half when you approach a turning, displaying a large icon representing that turning on one half and a 2D overhead moving map on the other.
But the good news for the Maestro unfortunately ends there. Why? Because, as well as the good aspects of the 1215, the 4245 also has all the irritations. It has the same ugly-looking green/brown mapping colour scheme and more seriously, the map doesn't present the correct level of detail 100 per cent of the time. At one point, while driving in London, I turned down a main street off the route to see how quickly the route recalculation was, and was surprised to find that the 4245 didn't seem to have that road in its database; it turned out that it did, but for some reason it hadn't displayed it on screen.
The problem with detail manifests itself most clearly in the map browse mode, however: you don't get to see full street level detail or road labels until you're zoomed right up close, and motorways are impossible to pick out at medium zoom levels, so if you're trying to plan a route via, say, the M6 toll road it's very difficult to do so.
Amazingly, for a top-end satellite navigation device, the Maestro 4245 doesn't have seven digit postcode lookup. Instead, if you type in a postcode, it'll more often than not require you to enter a street name and house number too. And its navigation and voice instructions aren't particularly polished either. The device seems to randomly lose its GPS lock and then when it reconnects it often gets confused as to where you are and what direction you're travelling in. The screen doesn't update smoothly, so in-town navigation can be hit and miss.