I remember Dandowoski saying the 4 tone was similar to the CZ3D/CZ70 4 tone setup. I've been using 3H (nickels moved to high tones) on my F70 & F5, and have been pretty happy with it. I've tried the 4 tone and it was OK too, but I thought the 3 tone option gave you less noise to listen too along with the aid of the VID #'s to help you decide to dig or not to dig. I've also used the 2F tone on the F70 when in thick iron and I thought it did well too, but couldn't really see using it for coin shooting a park or such (well unless it was infested with iron). I picked up a nice sterling silver pocket watch back a couple of weeks ago in an iron infested Nevada ghost town using the 2F tone option on my F70.
I guess I don't understand the purpose of 1 tone, I mean everything will give a single tone, so your eyes will be glued to the display. It seems like you might as well run all metal and get smoother operation, still using 1 tone. I guess the thought behind one tone is to dig anything metal, iron or not
I took the F75 LTD on its maiden voyage this afternoon for about five hours. I lucked out, the first target I dug was a nice sterling silver ring (been on a bit of a ring roll lately, this makes my 6th silver ring, along with one gold ring in the past 6 weeks or so)

No old coins, but I found some neat relic type goodies in an old spot, along with the ring and the usual clad in another spot. I was able to run the bP mode at 75 sensitivity with the first half of iron disc'd out and it ran super stable (that says a lot as this park is EMI central), and it seems to be going pretty deep (would've loved to find a 10" barber dime or such to be certain
I think I'm going to like using the LTD, luckily it's very similar in operation to the F70 which I have a LOT of time on, but a lot more feature rich and definitely deeper. I haven't tried the CL mode yet, but bP mode is looking good. When I switched between bP and DE modes, bP was hands down far better sounding on targets.
hh,
Brian