7x0 series, launched August 2007 was superseded in August 2008 by the outwardly identical 7x5 series which adds faster routing and lane assist function.
The 8x0 series, launched June 2008 added voice recognition.
The i models only had standard routing functionality.
A version of the i3 with pre-loaded map on built-in storage was released in October 2005.
The nüvi 370 and 670 models added intercontinental mapping to the capabilities of the 360 and 660 models.