Worthless. I spent $300 for a Gamefinder. There is so much scatter that you get a different reading from every leaf that is turned sideways and different size rocks , and absolutely nothing makes sense, regardless of the sensitivity setting, gain whatever they call it?
I was looking for an animal for about thirty minutes one night, back and forth, up and down. I think I could have crawled it on my hands and knees with a bic lighter and done as well! What really tore it for me was when my partner came out to give me a hand, and the damn thing couldn't detect him walking right out to where the animal was laying. This was a frosty night, I don't know how cold it was, but that animal should have been easy to detect. Not a bush over two feet tall, and there wasn't many. Cabellas gave me my money back.
My general rule of thumb, at night. Depending on the amount of blood, and if you can locate the spot. If a coyote can make it 800 yards, you probably won't get him....unless you have good snow on the ground and you can press him. However, under the desert conditions I hunt, it is very difficult to track an animal in gravel at night. A lot of those pebbles are the same color as dried blood.
What I'm saying is; it's tough dealing with a runner!
This is why I advocate using enough gun. daytime, a different story. You might be able to spot the animal from a half mile. But, at night, you need that animal to literally drop in his tracks, and you need to mark the spot precisely. Getting out there and finding that he has gotten up and run off can eat up a good two hours of prime hunting. Use a Swift, and they will be there.
Good hunting. LB