I'VE BEEN HUNTING WITH THE ACE 250 WITH THE STANDARD COIL FOR ABOUT 4 YEARS.I HAD READ THAT A LARGER COIL WOULD GO DEEPER AND FIND COINS THE SMALLER COIL WOULD LEAVE.SO I ORDERED A 9X12 COCENTRIC COIL ABOUT TWO WEEKS AGO.ONLY HAD A COUPLE TIMES TO GET OUT BUT HAVE ONLY FOUND BOTTLE CAPS AND JUNK.I'M HUNTING TWO OLD HOMESITES THAT I HAVE HUNTED MANY TIMES WITH THE ACE 250.ACCORDING TO THE OWNERS I AM THE ONLY ONE THATS EVER HUNTED THESES TWO HOME SITES.ONE WAS BUILT IN THE LATE 1800S.I HAVE FOUND SILVER OLD BUTTONS AND OTHER COOL FINDS BUT NOTHING WITH THE NEW COIL.A LITTLE DISAPPOINTED AND JUST WONDERING,IS THE BIGGER COIL REALLY BETTER OR ABOUT THE SAME?OR IS THERE A DIFFERENT LEARNING CURVE?THANK YOU FOR ANY HELP IN ADVANCE.HOPE TO GET ME A AT PRO SOMETIME LATER BUT FOR NOW,GOTTA KEEP BANGING WITH THE ACE.HH