I purchased a CZ21 a few years ago when they first came out. I think I must have bought a lemmon, because no matter what I did I couldn't get it to GB on the beach. I have been TH for 30 years and this was the first time I couldn't get a machine to function correctly. Anyway, instead of returning it to the dealer, I traded it in for a different detector. I'm actually considering biting the bullet and buying another one. Now that they have been out for a while, I'm wondering what other users think of their CZ21.