This is the one I have, and I use it all the time. I don't have a lot of experience with the other brands, but this thing does all kinds of neat and fancy stuff. You can download maps to it, create "tracks" (record your movement), mark different locations, and all kinds of other stuff I haven't figured out. I mainly use it sledding checking altitudes, and figuring out whereabouts I am in relation to pick up and drop off points when we're shuttling in the backcountry.
I believe it was about $400.