It's a fantastic detector. The good...Really easy to set up and learn. Simple and effective. Really fast for dual freqs (5 & 15kHz) much faster than the Etrac & Vx3 I had, SUPER deep, loves old deep coins. Noticeably deeper on planted targets than my ATP, ETrac, Vx3 and Deus were. Accurately picks nickels out from pull tabs. By FAR the best nickel machine I've ever owned. Great on batteries & works great on salt beaches too (just don't get the control box wet).
The not so good...some say it has an affinity for deep iron. A simple 360 scan walk around will tell you if it's iron or not 9/10. Not the lightest or best balanced detector but once the control box is hip/chest mounted, it swings easier than a Deus or a Compadre. Coil selection is a bit on the slim side only 3 that I know of (5", 8" & 10" concentrics). Note: this machine is NOT designed to use DD coil. May not be the best choice for heavily iron infested sites but I haven't had too much problem when equipped with the 5" coil. CZ-3D is Not waterproof like some of the other CZ's.
It might be older tech and it might be going the way of the dinosaur but I haven't used a deeper more accurate machine for old coins. I'm never getting rid of mine.
If you do decide to get one, send it to NASA Tom Dankowski. He'll tune it up for you and you'll have a much better running unit.