It tried to use it today. I'm in Kapaa, HI. I searched for "Bar Acuda" a highly rated and popular restaurant here on Kauai. iOS 6 maps gave me some place in Spain. Tried "Bar Acuda, Kauai" and was told "No Results". Tried iOS 5 with just "Bar Acuda" and it found it first try.
It's not just the quality of the maps that's an issue. It's also the quality of search. Google maps isn't perfect either but on top of having better map data is has better search so for example searching for "gauteir exhibit, sf" actually finds the De Young Museum in San Francisco even though I didn't name the museum nor did I spell the name correctly. IOS6 maps just said "no results"