I still think overall, the 8 inch coil is the best coil for the CZ. Even beach hunting. I use the 10.5 and the 12 inch Sunray for coverage and a little more depth on the beach, but it seems whenever I hunt with the 8 inch coil, even on the beach, I find the best stuff. I use the 8 inch coil the most even on the beach.
The 5 inch coil can be cranked up a bit in terms of sensitivity, and can sniff out silver or copper with the best of them when there is a lot of modern trash around. It just takes more time to cover the area because you still have to have a moderate sweep speed.
My opinion...since you kill trashy spots with your small Sunray on the Explorer, stick with that set up.
If you do get the small coil for the CZ, I would love the hear your opinion on it in relation to the 5.5 Sunray. Thinking of getting that coil for my E-Trac but also have the 8 inch Sunray as part of the debate.
Matter of fact...I am going to PM you. If you want to try the small coil, I can send it to you.
JC