FWIW, and noted by previous posters the type of collar system you're looking for matters. Garmin bought Tritronics and by most accounts Tritronics was the gold standard in terms of durability and reliability. I happen to be an Alpha 100 user and cannot say enough good things about it. I've not experienced any of the challenges some have and I've been running with them for 4 years and zero issues. SportDog bought Innotek and by many were not nearly as reliable as Tritronics back in the day. With that said, I was an Innotek TT1600 user and liked them a lot and had little issues. In fact, I still use their launchers. Innotek was way ahead of the curve on an integrated system, I believe they were also first to market with GPS/training combo collar. I have no direct knowledge of how well or not the the SportDog Trek system works. I do have a hunting buddy that used the SportDog track and beeper combo and liked it. He had to replace collars a few times, but we're putting lots a miles on the ground every year. I have no direct knowledge about Dogtra except for a bark collar and I liked the compact straight forward nature of the collar. I share as someone who's purchased many and used lots. To the point someone made earlier, all three are top tier and their specialty perhaps slightly different so what type of collar system you're looking for matters. Good luck