I would stay with the Ace 250 and buy an extra coil, the larger coil or the smaller coil or both! That Ace packs a lot of good technology, just does not get as deep as the high dollar detectors. A friend uses an Ace and I was using a White's XLT, he found the same coins and relics as I did but I could get deeper targets. My X-Terra 70 goes deeper than my XLT and seems to be more accurate on IDing targets. If you upgrade, think about this, do you really want to dig a 12"-18" hole for a bottle cap and an occasional coin or relic? I would buy a new coil or both coils with coil covers and a pinpointer, would be cheaper with all those accessories than buying a new detector to learn. Learn your machine, it takes many hours. The Minelab detectors are nice machines and they get some good depth and target separation, that Ace would make a nice backup detector to the XT30. HH and good luck on your choice, Mike