The Garmin BlueCharts are superior to the competition. I have yet to see a
GPS/chartplotter review where Garmin charts were anywhere but number ONE.

I think you should read a few more reviews. Navionics produces raster charts
which are considered the most accurate and the ones reviewers and everyone else
considers the best electronic charts. Garmin ain't doing raster charts.
S/V Express 30 "Ringmaster"
"Trains are a winter sport"