I haven't tried the satellite communications yet and can only speak about the GPS. This GPS receiver is packed with features but the menu set is not intuitive on how to use them. A quick start manual is included with the unit but it's pretty basic so you need to download the owner's manual from the Garmin website. The owner's manual provides technical details but is lacking in how to really use the unit. An example is the instruction set for "Creating a course". Last instruction is "9 Select Done." There isn't a Done button on the keypad and the instructions don't tell you that you have to press the "Quit" button before you are given a choice to press "Done" If you try to activate the course the manual terminology doesn't agree with the icon on the receive and the instruction don't tell you the to find the go button you have to scroll through the icons at the top of the course page to find a Go icon. This morning I was walking a course I had set up for practice. I don't know what button I hit during the walk but it dumped everything I had saved. Glad I wasn't deep in the woods somewhere and it makes me wonder about reliability.