My sister moved since I saw her last so it was a great opportunity to use the new Navman, and I love it. It's so relaxing following clear directions and never making a wrong turn and getting lost. It also has some other unexpected good features: speed camera warnings, a (too loud) ding when your average speed goes to high, and traffic updates on your route, not that I've had to deal with avoiding a jam yet, but it's great knowing that I can. Not so good is it not being very accurate about speed limits; they don't always match reality.
The pronunciation of street names is a source of amusement. We first used an English woman who was fine (apart from her attempts to say Maori names) till we went down a dead-end street to look at the University wind tunnel and she kept saying "Make a U-turn now" in a voice that made Greg say, "I am the weakest driver". We're now using a laid-back Aussie guy, but he's no better at saying street names. Examples of weird emphasis: Macfarlane, Gordonton, Marshmeadow rhyming with "cow"
Examples of mangled Maori names: Ngahue becomes Ingahoo, Puketaha becomes Puhkeeta, Manukau is Manna-caw
My favourite so far: Anglesea as An-glay-see-ah.
Also posted on Dreamwidth, with comments.