I can"t justify buying ANY of them. I pay for all of my hunting and fishing by recycling metals. I am very carefull with those funds. When I do buy one, it will be 5 years old, and cheap, or I will have to pass it by.I am well set up for gear, but cameras and mussleloaders will have to wait.
The only real difference between a good tracker and a bad tracker is observation. All the same data is present for both. The rest is understanding what you are seeing.