Brian, I have the old Tritronics Sport Dog G3 and the Garmin GPS on both Brittanys. My purchase predated the gps/ecollar combination. In thick cover chasing 'doodles, a bell is sometimes not enough. Have you ever had to find a young dog that jumped a deer or hog? Well, I have. More than once. <g> A buddy has a stone deaf Brittany who is dynamite on woodcock. She was 13 last season. He borrowed my tracking collar and we had to look for her several times and found her locked down on point twice. We were in thick cane and she couldn't see us to find us. With the gps collar, she was easy to find. She wore a bell but was beyond hearing distance. A Georgia trainer has the best story I've heard regarding the value of a gps collar. She was working a dog around an old barn. The dog disappeared. The collar pointed to a the barn. The looked in the barn and couldn't find the dog. The locator pointed to the wall. The dog was wedged between a wall and a stack of lumber. The dog was head down and exhausted. She would have never found the dog without the collar.