Re: GPS/Fishing finder/Charts?
How did you determine that Navoincs got you the closest? I can tell you they're missing a major (i.e commerical) navigational bouy in my neck of the woods.
If you pay the annual upgrade fee you get the most up to date charts. As with even the most expensive nav systems, you are not going to load it up once and forget it. Things change rapidly on the water and accuracy requirements are also dictated by the intended use.
I use the USCG Nav sights to get the latest info when I need it. If I'm going to a lake that I've never been to I send an email to Navionics and get the surface water elevation at the time the maps were produced. I then use my sonar and the maps contours to determine the current surface water elevation. That'll tell me where the shore line is and where any new obstacles are.
I have to admit, there was a time just a few months ago when i got completely anal and PO'd about the maps not being accurate and then a light bulb went on.