navigation for windows phone 7

Just a quick survey to see what everyone is using. I'm located in Canada so unfortunately navigon isn't an option.

Nokia Drive seems to be missing a lot of addresses in my area.

I was looking at Garmin, and the no offline maps doesn't bother me too much - but no trial on the Canada marketplace so kind of weary. Does anyone know if you're using navigation while playing music, does it lower the volume of the music when it's announcing? It seems like no navigation apps for wp7 do that. Is that an API issue maybe??

Anyways, would appreciate your input. Thanks.