Re: GPS, Best Bang for your buck
I'm also a big fan of the handhelds. Garmin is highly recommended for ease of use, features and reliability. I take mine in the boat, car, backpack, canoe, hiking etc etc. I have complete topographical maps for all of Canada, full marine maps for North America and the latest autorouting road maps of all North America. My Garmin Vista has all the performance and MORE features than most automotive units.
By "a bit more power", do you mean bigger display, more features? GPS units don't depend on more or less power. They only receive signals. The newest receivers incorporate high sensitivity chipsets thereby improving sensitivity when in heavy bush or in confined urban areas. Out on the open water, pretty much all units (handheld or fixed mount) will perform equally well.
WHat features are you looking for? Dedicate GPS or GPS/fishfinder combo, color or B&W. What is your budget?