Is Nokia's GPS still supreme?
If my memory does not deceive, it was called Nokia Maps on 5800 Xpress Music mobile phone and once it had GPS signal you had a marvelous GPS experience..
It was dominating even the GPS devices
Depends on where you live. If you're not in the US/Europe, the Bing/Nokia Maps database can be really hit or miss. I find that it maps locations pretty well when you give it a specific address, but if you're trying to find local businesses or POIs, a lot of the smaller ones aren't going to show up.
Having said that, the capabilities of the maps/navigation app itself is at least on par with Google Maps on Android, and is much faster, easier to use (less steps required for just about everything), and MUCH smoother and less laggy by far when you're scrolling around (comparing to GMaps on Nexus S running ICS here). You get voice directions too, just like Android. And an unofficial gMaps app is available for Windows Phone, if you really can't live without it.