really does look like an impresive bit of kit!
Its not, NCDx sat nav is very poor and very basic.
You cannot do a postcode search, and sometimes you cannot put in the house number in the road you are finding, it asks you for an 'intersection' only which is crap if you have never been there so you don't know what roads it intersects with!
You will be suprised how many roads there are that have different postcodes and if you dont 'guess' the right 'intersection' you can end up in totally the wrong place
That opinion above is based, by the way, on using an NCDC 2015 for the last 2 months with the latest 2008 disc and updates, I also have the telematics, which is ok, rest of system is basically the same as above but i also have the air con distribution options as part of mine
Its a decent, and VERY accurate system. Yes, it can't do postcodes, that may or may not be a big issue for most.
As for the house numbers, it depends on the map, and both Navteq and Teleatlas (the only 2 mapping companies) are approximately the same for house number coverage (both pretty poor).
It lacks warnings for POIs, and no easy way to upgrade POIs.
Where is scores massively over handheld stuff is accuracy - no portable unit can get close to any fitted unit.