I only use the 17" coil and I hunt some pretty trashy parks. My silver count has gone through the roof since I started using it. I agree that the ability of the CTX even with the 17" coil to sniff out coins amongst the trash is incredible! If I get a good coin signal, I will use the pinpoint, but I pinpoint to the coin/target under the center of the coil and turn 90 degrees and keeping the center of my coil in that imaginary line I pinpoint again. Essentially the + method and it is very accurate. If it is really trashy and the pinpoint want to pull off to one side or the other, I will use the pinpoint to center the coil over the coin/target and do the wiggle back method, again pretty darn accurate.
I find that the CTX is deadly on the coins and will hit through the null and let you know a good target is there.
Also with the CTX, those deeper coins ring loud and true. Earlier this year, I dug a Walker and a SLQ in the same hole and there were every bit of 12".
I have a few videos of using the CTX, just the finds, not live digs at my youtube channel: drj8ke