I've had the Chaser since November 5 and have put in 2 half-sour sessions so needless to say, I've just started the learning curve. Seems like it is going to be a great all around detector. In the instruction manual to one of my Garrett detectors, it says that the patina on an old coin can cause discrimination at any level to cause the coin to be rejected. I haven't verified that as a fact.
My 2 first sessions have been in coin, tone ID mode. I found a silver earring on the last trip. I have a couple of indian head pennies filed away somewhere and will try those in coin and relic programs. One of the pennies does have a heavy patina, so could be a good test item.