What do you use offroad to keep track of where you are going, where you've been?
I've used GAIA for the trail riding I've done and its worked pretty good. Is it perfect? No but I am running it on my iPhone (which you can also run it on any Android or iOS device with GPS) and so I don't need to have multiple charge ports (1 for a GPS unit, 1 for my phone).. just keep it charged and hundreds of possible mounts for a phone versus a certain GPS unit.
NOW the negatives, obviously an iPhon