Based on advice from Uncle Willy and others, I purchased an ACE 250 as a backup for my GTI 2500. So far I have been surprised at how well this little "yella fella" works. I have a couple of questions: Is it worth while to buy the larger coil or the sniper coil? I know that the sniper is for "trashy" areas, but I don't know how much junk would make it worth while to use the sniper. I also has a situation in a school play ground that has lots of foil, etc., where the detector starting giving constant signals that went up and down the scale. I turned it off, then back on, but that didn't help. After I moved to another area, it stopped giving those returns. Any ideas? 