As far as new roads is concerned I do prefer Navteq to Sensis, at least on the Eastern seaboard. Some ppl will say that Sensis has better b/in pois, but even if that's true i'd rather have more up-to-date roads and smell my way to the nearest Maccas. Garmin started loading Navteq exclusively onto new Nuvis in early 2012. AFAIK all upper-echelon 2012 nuvis [3490, 3590 etc] were sold from then with LM Navteq so there are no ASR'2' files available for Sensis maps, only ASR'1' suitable for 2011 devices [e.g. 3790, 2460].

If that original image map i uploaded doesn't work properly in your 3580 after unlocking, i'll eat my hat.
NB: I don't wear headgear.