I went from a MXT to the Xterra 70. The MXT seemed like it could not get past the 8" mark, even with the stock coil. I tried the "Super 12" and it was "OK"b but the weight of the set up was terrible!! I got my Xterra 70, went out to my "Beat To Death" CW camp and started finding targets the I had missed with the MXT. I was finding so much that my hunting partner, who had a MXT also went that next week and bought a Xterra 70. Now we both use the 10.5 DD 7.5kHz medium freq coil. No problems at finding targets at 10-12 inches. Now they are not real strong signals, but better than the MXT going from low to high tones at 6". The MXT will detect deep, but only will give a low tone until you remove soil and check the hole, then it will hight tone if the target is brass or lead...............Mark