Not many people realize this, but a CZ-70, cz-7, and cz-6 can be run clear into the lowest amount of discrimination (allowing iron and everything else too) using notch and get EXTREME depth on coins on the nasiest of beaches. I got more depth out of my cz-70 doing this than I do with an Explorer, Sovereign, Compass, DFX, or any other detector searching in zero discrimination. When I bought my cz Fisher told me this would be the case, and they knew what they were talking about. If I told you the depth I get you wouldn't believe it, but it's fantastic. In this mode though and using such low discrimination I get about two more inches of depth than in all-metal. If I cancel iron I get about 2 inches less, a substantial difference, but the audio works full-time anyway, and so does the bell tone for big targets. In iron discrimination though, the Compasses ALWAYS beat the other detectors for depth on high salt/iron beaches...
I would consider a cz. And BTW, in over 3 years I've only found 4 nails with my cz.