It is a great coin machine and it does much better in iron than the 3D. In my East Tennessee soil it gets a little more depth too.
I might add that it has a much better user interface and has many options for settings that make it extremely versatile. It can pretty much mimic the 3D's old coin feature and it can read high coin on nickels.
I have to be honest here and tell you that I never was very good with the 3D, and usually chose to hunt with my Explorer XS over the 3D. However, now that I have the F75, I usually choose it over the Explorer SE if that tells you anything.
Not to knock any of the 3 as they are all great detectors that are very capable of great finds. I love my relatively new SE and wouldn't part with it for anything. But for ME right now, I'm having more fun and success with the F75. I own or have owned the CZ3D, DFX, XLT, XS, SE, Nautilus IIBa, 1236-X2, and the F75. To me the best coin machine I've used might be the F75. The XS/SE is formidable, but the F75 so far is hanging right there with the Explorer, and might even be to a tad better in iron.
Of course this is just my experience so far. I haven't used it enough to lower the 1st bar on the battery meter even though I've used it for 3 weeks.
Others may see it differently than me.
I also feel like the results will improve for F75 users and they share tips and experiences here on the forums and learn their machines better.
HH Alton