We've banged on about the efficacy of HD Traffic at great length in the past, and even written a feature about it. But this is because it was a revelation when it was launched, and it appears to have improved over time, too. Amazingly, despite HD Traffic being around for three years, its abilities have not been surpassed. Other than this you get the Google Local Search online points of interest system, plus dynamic weather reports, and the ability to send notification of traffic camera locations on the fly.
Other than this, the Top Gear Edition has a complete set of basic features. You can navigate to a full UK post code, and plan multi-waypoint journeys. There's no keyword search across the address database, but this is possible with the points of interest catalogue. Journey calculation uses TomTom's IQ Routes system, so takes into account real historic road speeds rather than using nominal speed values, so estimated time of arrival is more accurate than traditional systems. Essentially, this is a very capable mid-range sat-nav which will get you from A to B as well or better than most devices on the market.
The Top Gear Edition TomTom was always meant to be a limited edition, through Halfords only, so reports that the BBC was pulling the plug seem to be a little overstated. The company was only going to make a certain number, and allegedly have already done so and won't be withdrawing anything from the shelves at te behest of the BBC. When they sell out, they're gone. Or, at least, that's what we've been told, and it could just be a publicity stunt. Either way, there will be a finite stock of these devices, of indeterminate size, and it will cost you around £30 for the extra features and exclusivity compared to a vanilla GO LIVE 820. The latter can be found discounted online, whereas the Top Gear Edition only sells at Halfords at TomTom's RRP. Whether you think this is worth it depends on how much you, or whoever you're buying for, likes Top Gear, and in particular Jeremy Clarkson's brand of humour. If you do, then this is great fun, at least for a short while. And after that, you've still got a corking sat-nav.