I have not gotten to use the GPS much until now and yesterday it worked great! I am very satisfied with my purchase and the free maps (florida topo) I found at GPSfiledepot.com.
I put on nearly 19 miles yesterday and it tracked every little movement including telling me how much time I spent standing still. I added my waypoints at the house using the supplied Map source software it was very easy and adding waypoints on the water is simple too. The unit is very easy to operate and I can switch between map, speedometer/odometer, and directional screens with one button. After 5 hours on the water I still had a full battery even though I had the screen on half light most of the time. When starting up the device it did take about a minute to get the satillite signal and get loaded up, but once going it was very accurate. Even though I have detailed maps loaded in it still drew the maps fairly quickly. I thought the small screen might be an issue but it wasn't, since everything is so well layed out it was always easy to see what I was looking at.
Overall I have to give it a thumbs up.