GPS based navigation is fairly standard these days and that's a good thing. No more arguments over a lack of map reading skills or keeping a number of cumbersome maps in the car, one small unit does it for you. If your car doesn't have it built in, there's an increasing chance that your cellular phone will provide that functionality. However still the most popular means of getting GPS functionality is through a standalone unit. Motorola known for their portable phones, thought they would try their hand at the GPS game; they really shouldn't have.
The TN20 has most things an up-to-date GPS receiver should. Compact dimensions, clean lines, a touch screen and text-to-voice instructions. The unit comes preloaded with maps of the continental United States and has a claimed one million points of interest. While all of these features are great the implementation is far from it.
It would be harsh to completely pan the TN20 as for the price the features it holds are good. Coupled to the fact you get a windscreen holder for the unit the value for money is certainly pretty high. It even looks good, with a black and dark grey two-tone finish which looks good on the majority of car interiors. The included car-cigarette charger has a long cable and with the relatively woeful battery life meaning you'll want to have it plugged in for anything but the shortest of journeys.
One very noteworthy feature is the 'lane director' feature, which tells you which lane you need to be on in order to continue on the correct route. For those of you not familiar with US freeways, many feature four to six lanes with one or two often providing the exits or transfers onto other major roads. It's not only a matter of avoiding the incorrect exit but not ending up on another exit by mistake. The TN20's lane directing feature is one of the stand-out aspects of the unit and saves a lot of last moment, bare knuckle lane swerving.
Motorola had the right idea with the user interface for the TN20 however the menus are slow to react and when entering place names, the touch sensitive keyboard is completely useless. Key presses aren't recognized or alternate keys are recognized. Even if you have someone else in the car helping you to do this, it's far from fast. If you are expecting iPhone-esque touch screen keyboard you will be sorely disappointed. The menus are fairly intuitive but inaccurate registering of keypresses remain frustrating at best.
We tested this unit during various trips throughout Massachusetts, Rhode Island and California. The time required to get a GPS signal varied depending on the location of buildings but in a city expect anything up to a minute but on the whole was slow compared to older units and the ‘cell assisted GPS’ on an iPhone 3G. Also expect to lose signal if you are under a bridge for anything more than a few seconds. GPS signal aside, routing is poor with no concern for prevailing traffic conditions; leading us onto routes which were congested. On one trip to Los Angeles Airport (LAX) not only did it fail to recognize the street we drove upon for a mile but at the intersection got so confused that the monotonous drone inside the unit kept on repeating "go left then go right" swapping left and right every so often. After this it failed to recognize the road we were on and again took us in the wrong direction. Final result? Paying the airline for a new ticket.
Routing problems aside, the points of interest were a hit-and-miss affair too with gas stations being missed or being sent to ones which are needlessly miles away. Compared to other units the number of points of interest is too low.
Motorola's TN20 is an entry level GPS unit and is priced accordingly. The problem is it can't do the entry level functions well enough. In our testing (over 2000 miles of driving throughout cities and states) numerous times the unit lost GPS position, sent us down wrong streets and in some cases was outright wrong. A lot the TN20 problems stem from the very poor touchscreen which is more hit 'n miss than a blind man at a shooting range. The 'lane director' feature is extremely well implemented and provides a rare glimmer of sunlight in an otherwise poor product. However this is not enough for us to recommend this as a capable GPS unit. Your money would be better spent on units from TomTom or Garmin.