bought the premium accuterra maps, though the 3 layer maps are no longer avail as of 2013, only an updated single layer. An improvement over regular maps yes, but for $20 add on i expected the 3 layer.
"As of 2013, the Accuterra Map Source is becoming a single layer source, for greater performance and ease of use. It will also have full data for the continental US up to zoom level 16, which is a plus. It has roads and trails as a separate layer that can be used on top of other maps, as discussed in the next section on hybrid options. "
So now you can add trails ontop of the other viewing options incl. an aerial map, which can be helpful for some
"As of 2013, the Accuterra Map Source is becoming a single layer source, for greater performance and ease of use. It will also have full data for the continental US up to zoom level 16, which is a plus. It has roads and trails as a separate layer that can be used on top of other maps, as discussed in the next section on hybrid options. "
So now you can add trails ontop of the other viewing options incl. an aerial map, which can be helpful for some