The MIO DigiWalker C310 is the second product in the company's current range of dedicated in-car GPS units. Designed as an entry level model, the C310 is almost identical to its big brother, the MIO DigiWalker C510, only without certain features including a Bluetooth hands-free and a photo viewer.

The C310 is identical in shape to the DigiWalker C510 but with a different white and grey finish. This is one of the few GPS units on the market in a colour other than black or grey. Measuring 112mm x 76mm x 20.6mm and weighing 170g, the C310 is on the smaller side for a dedicated in-car unit. Unfortunately, the same stubborn window mount seen on the DigiWalker C510 is included with the C310 as well. The mount makes it difficult lock in and remove the GPS from the clip, meaning those that like to carry the unit around with them may get frustrated.

Like the DigiWalker C510, the buttons located on the left side of the unit are the best design feature of the C310. Their rubber surface means they are comfortable and easy to press, so adjusting volume and navigating back to the main menu is effortless. Unfortunately, they aren't backlit, so finding them during night time driving is a little difficult. As with the DigiWalker C510, it's nice to see the C310 with external volume controls, as some other units this size don't have them.

The impressive 3.5in touch screen performs well in direct sunlight and has an excellent viewing angle. For night time driving, the screen is bright and clear, with colourful menus and easy to read icons. We were particularly impressed by the night time maps; the background is dark with a bright green navigational line tracking your journey through streets, whereas the day time maps have a lighter background with easy to read street names.

The menu system is a mixed bag. The MIO Map main menu is excellent, with clearly labeled, coloured icons and a text description making it easy to navigate your way through the device. However, some of the submenus feature smaller icons with no text and these are difficult to make out. While some are obvious, others - such as a winding road with a flag - are hit and miss, especially for first time GPS users.

More impressive are the maps on the C310, especially when compared to previous units. MIO has used Sensis V13 mapping this time around, and these are preloaded onto the 512MB of memory. There is an SD card slot on top for extra maps. You can quickly change the C310 map view using the cycle maps icon in the top right hand corner of the screen; the unit offers standard 2D and 3D views, with north up, track up and sky view maps as well. The latter is represented by a picture of a plane and is really only useful for a full view of your closest surrounding suburbs, rather than during driving. The maps have a good amount of detail, with street names easily readable and the current location clearly marked by an expanding circular beacon, much like an alarm or distress signal icon.

The C310 is equipped with the latest SiRFstar III GPS chipset and we were pleased to report its performance is fairly speedy. During our driving tests, we found the unit took anywhere between 30 seconds and a minute to pick up a signal after being turned on. It was quite quick and generally responsive, and managed to maintain a GPS signal despite an obscured view of the sky at times.

The navigational experience was fairly pleasing thanks to clear voice instructions. Our only complaint was with the relatively soft volume levels, even at the highest setting. There are a wide range of languages to choose from including German, Italian, English, Dutch, Spanish, French and Portuguese, amongst others. The voice is clear and concise and generally quite smooth. Despite the somewhat confusing sub-menus, the C310 isn't too difficult to use as most of its operations are accessed via the MIO Map main menu. Tap the relevant icon to navigate to a specific address, a POI (Point of Interest) or saved favourites. The map can also be viewed without actually navigating to a location, and recent locations can also be checked.

When searching for a specific address, the C310 doesn't filter suburbs by state, so unfortunately you are presented with a list of every suburb in Australia. Although it does narrow down the search when you start typing, we'd still prefer to be able to select a state first, then a city. Once the city is selected, the street name - filtered by suburb can be chosen. The address entry screen uses a large on-screen keyboard, but the keys are small and those with large fingers may have difficulty with precise selection.

The usual routing options, such as avoiding tolls and unpaved roads are all supported on the C310. Users can also set a preference for using motorways or normal urban roads and this is taken into consideration when the unit calculates a route. MIO has also included up-to-date speed camera and red light camera warnings as well as a safety mode which doesn't allow you to operate the unit while in motion.

The C310 also allows you to store other files on the unit's 512MB of flash memory, including contacts and MP3 files. In the main menu, you'll find a contacts list and an MP3 player. The latter is quite notable for a GPS unit (especially one that is marketed as an entry level product) as it includes a full 10-band equaliser, playlist support and play modes such as repeat, random, intro and sequence. Furthermore, you can synchronise your Microsoft Outlook contacts from your PC to store them on the C310's contacts menu, although this function would have been significantly more useful with Bluetooth functionality, as seen on the DigiWalker C510.

The C310 internal battery is rated at between four and five hours by MIO, depending on usage. Do note that the volume levels and backlight brightness will all affect the length of battery, so this is a variable figure. On average, we experienced about four hours of use before a recharge was required; slightly more than the DigiWalker C510 as this model doesn't have the Bluetooth hands free feature.