I have an Astro unit and absolutely love it. I coonhunt 3-4 nights per week, sometimes my hounds may range out 1/2-3/4 mi to find a track. The Garmin shows every step they take. As a training tool its has no equal, the Garmin tells me when my dog hunts covered ground, tells me when she is working a back track or even when she is paying too much attention to other dogs while hunting. Not to mention I can tell what side of the creek or river she's on or when she gets close to roads.