I purchased two similar maps of Kauai: "Franko's Kauai Guide Map" Franko's Kauai Guide Map and James Bier "Map of Kauai." Both have the same scale, approximately1:160,000 or 1 mile = 0.40 inches. Both show more detail than my AAA Hawaii map (which covers all islands).
The Franko's map is copyright 2007 while Map of Kauai, 7th edition was copyrighted 2004 by University of Hawaii Press. Unfolded, the Franko map is 21x14 inches (53x36cm) and Map of Kauai is 22x15 inches (56x39cm). The Franko map uses water-proof, tear-resistant material while Map of Kauai is printed on heavy paper that is not water-proof or tear-resistant.
Both maps use shading to show mountains and valleys. The perimeter of the Franko map is filled with text describing points of interest. Each POI has 2-4 sentences with a line connecting the text to a map location. There is a lot of useful information on the Franko map but the text is small and you can't scan the map to pick out points of interest - you need to stop and carefully read. The Franko map is dark and it's difficult to read the small print on the map. Map of Kauai is a "cleaner" design that makes it easier to quickly read.
Both maps have inserts that show more detail of urban areas. On the Franko map, the reverse side has detail of the North Shore, East Shore, South Shore, and Na Pali Coast & Kokee Hiking. On the front of the Map of Kauai are inserts of Kapaa and Lihue while the reverse has an insert of Poipu. Also on the reverse of Map of Kauai is a good index of more than 1000 points of interest and streets.
I'm a map geek and I like both maps. The Franko map is useful for planning what you want to see and do while Map of Kauai is handier to have as a navigational aid. If I had to pick one, Map of Kauai fits my needs better. I wish it were more recently updated.
Franko's Kauai Guide Map
Map of Kaua'i