I voted Navionics as that is what i now have( allthough I have used other cards previously).
I just purchased a lowrance LMS527 with the Australia Wide Navionics card and have been playing with it in the backyard and the weather in the last few days has not been boat friendly.
Overall i have found the chart data to be great. Just cant wait to get it in the bay for a decent test run.
Quinny