Lowrance Insight HD Maps VS Insight Maps
I received my HD map card today so I tested it on both of my HDS units. It works on either Insight or Basemap. As I'm sure you know the basemap mapping sucks. The Insight shows good enough detail, but for the same money you can get the Lake Insight HD card. I'm hoping this will help anyone considering an Insight unit over a Basemap. If I had it to do again, I'd have 2 basemap units and 2 Insight HD cards.
This is the Built in insight map, you'll notice the contours on both.
http://i.imgur.com/tOuEg.png
Now for the Insight HD. (the dotted blue line is the train tracks)
http://i.imgur.com/1siFo.png
With the built in insight map, you get some shaded relief but you have to be zoomed out so far that it's not even useful. The insight HD will zoom in to 100FT with shaded relief.