The G800 is the first sat nav we’ve seen that uses full colour satellite photography for its mapping, the idea being that you’ll recognise your surroundings better when in unfamiliar territory.

The device is relatively compact with a simple power switch on the outside. It comes with maps of the UK and Ireland preinstalled and 8GB of memory to store additional maps or media content.

The G800 is quite well featured in terms of media support and extras, and from the main menu you can choose to play back photos, ebooks, music or video, or play a range of preinstalled games on the large 4.3in touchscreen display.

There’s also an FM transmitter to listen to tunes and directions through the car stereo, a Bluetooth receiver for your phone and a safety camera database.

We were keen to see what the photo mapping looked like so took the G800 out on the road, only to run into the first hurdle.

Ndrive’s photo mapping is currently only available for a limited number of UK cities. There are 29 available at the moment, but Ndrive says it is working to include more (see the full list on our website).

We were pretty impressed by the quality of the images and performance. It certainly adds a bit of dynamism to your traditional road displays.

When you can’t benefit from the photo mapping the device switches to standard maps which, while clear enough, did look a little bland.

The photo mapping certainly looks nice but it’s important to remember that this is just an aesthetic quality and, while it’s designed well enough not to affect the clarity of the directions on-screen, the G800 needs to get the basics right in order to be a success. And in our opinion it doesn’t.

Navigating a route, or indeed navigating the menus in general, is quite a frustrating process. Most damning of all is the fact that you can only navigate to a five-digit postcode – something we thought we’d seen the back of.

This means you frequently have to enter full street names and addresses to get to where you want to go. And with the small on-screen Qwerty keyboard demanding a precise touch, all but the most dextrous of individuals will need to resort to using the built-in stylus.

The unintuitive menu structure carries through to the rest of operation as well, where we found more holes in the Ndrive’s armour. The most notable being that, despite our best efforts, we couldn’t find a way to view a route itinerary once we’d planned a journey.

Meanwhile the volume control is buried within a couple of menus, making it particularly frustrating to adjust. These are two key areas that we always like to see accessible directly from the main screen.

Elsewhere there’s a particularly poor array of settings for customising the main interface or information provided while driving.

By default, you don’t get a lot of information provided on the journey, and the on-screen buttons that allow you to zoom in or out, open the main menu or view GPS status are particularly small and fiddly to operate.

We like the photo mapping features of the N800 (when available) and wouldn’t be surprised to see the system mimicked on rival devices in the future. However, it falls down in too many other areas, and, while basic mapping and directions are accurate enough and easy to follow, the usability of the device and general integration of extra features makes it extremely frustrating to use.