We used Shonky maps with our Garmin GPS on Hinchinbrook Island earlier this year. Up till then we had used the Tracks4Australia pro maps but found them lacking in detail for bushwalks. The Shonky maps were much better (but I still find the tracks don't accurately reflect the actual track walked.)
If interested, check out the link below. I did 3 screen shots off Mapsource of part of the Hinchinbrook Island track comparing where we actually walked with the Mapsource base map, Tracks4Australia map and Shonky map. There is a big difference.
We also occasionally use digital (scanned) maps in OzExplorer but find it a bit clunky and have not worked out how to load an index map so the 1:25000 are a pain to find!
http://frankinoz.blogspot.com/2007/10/gps-question-which-one-for-hiking.html