I have the Bounty Hunter tracker IV, and it has done me right so far, I haven't had allot of experience, but I have found that when it sounds off, theres something there. It takes alittle time to get the hang of what is there,,, Like I was told, I took some coins and laid them around and just tried to see how easy they were to find, when I was close, it rang out. I have also found they do hit deep targets, I found a nickel, which isn't a big find, but I was to my elbow till I saw the side of the coin, so I think they're pretty good, I don't know about service though. You may want to talk to Tony in conn. on his thoughts of a good model. smg