I was answering the question of what made me choose a Microsoft phone. Offline maps has always been a strong differentiator of Nokia, now the owner of Navteq. I can't comment on the quality and extension of Open Street Maps. I gather that you are a satisfied user of osmand, so I recommend that you don't do anything different.
Eh, I'm satisfied as to use in the US. The quality of the mapping they have for China is pretty bad... but I kind of figured it wouldn't be great from any other (english-language) provider either. Google Maps is better in some ways, but hard to access and still terrible at things like street addresses.
