I started using Ferrous Audio about a couple months into using mine, and ben using it since.. about 8 years now.. Mainly because of iron high tone falsing in conductive.
But I found also for the type of detracting I do most at cellar holes and other places with lots of iron, it made it easy run run almost in full accept.. iron mask with only one notch of disc that I can easier tell the less ferrous things from the iron.. many good items come in the lower conductive part of the screen. small buttons, pewter buttons, nickels, gold rings, cu/ni coins like flying eagles and 3 cent pieces etc etc.. I prefer to be alerted with a higher tone on possible good targets, as I find in conductive I tend to ignore those low tones more, and have to deal with high toned iron.. If your in a place free of iron, then its not that big of a deal when using such a wide open screen. Then again if little iron you don't need such a wide open screen either.. but lack of iron generally means lack of targets too.. where people were there was iron something or other.. at least in the old days..
A couple things that might bother you in ferrous in a park or yard.. crown caps will give a high tones, as will tin can lids.. however you are very safe notching that bottom right corner and not knocking anything good out.. occasionally a nickel or like target will bounce over there.. but its not very often.. Crown caps will for the most part stay buried solid in that lower right. Tin will read far right a little higher up, but not up into the silver coin area.. a medium cursor of disc on the right side half way down to bottom will knock out teh response from most of that
Another thing in ferrous is nickels, most pulltabs, small cents and some small silver half dimes 3 cents and screw caps read about on the same ferrous line.. so will give more or less the same tone.. so for that area you need to listen to the quality of the sound as well.. round targets will give a distinct good response over tabs and crap.. Aluminum seems to have a tonal quality of its own, and may well have it in conductive as well.. So using it for me is not a prob in parks and modern trash, as I just have my ear tuned for that good sound of brass and silver.. And if it really gets bad where they crap is all over, and I just cant take listening to it I can always switch to an open upper right block and just go for silver, most cents and big coppers.. ignoring the rest.
a big plus is you will get a noticeably higher tone on silver and large coppers, over other targets which read more left.. just make sure your variability is set full..
I think its a matter of preference and once you get used to one you will do well with either.. It was mainly the high toned iron and falsing that made me switch