I had the chance to pic up a whites classic III Plus and classic idx.... Impressed with there depths and coverage with the 9.5 blue max coils. None of them have mods, however they get great depth in my clean soil. My wife dug a 1798 draped large cent at 8" while the sensitivity was set to preset. Crazy thing was it was found in our yard. I noted the classic III Plus is just as deep as the idx... Best part is they can be had around $100 + or - the ones I have were made around 1998 to 2001.....it just show they still rock. I wish the idx had tone I'd, but the signal tone audio is better then other anolog machine out there.