I don't know much about pi machines. I live in south louisiana and are soil here is very neutral. Will the atx perform better in neutral soil? Also wanted to know about its discrimination abilities in iron infested sites. I currently use the AT gold with great success. Is it worth trying out this machine? I would deffinately like to be able to get more depth. Also would like to know if it uses multiple or single tones. Any help would be great! Thanks...HH