I wanted to say that I have had a whites mxt and a Fisher Gold bug Pro and now have the Garrett ATG. Of all the detectors, the ATG is the only one that I have actually found gold nuggets with. I am up two nuggets one was 3.4 grain and the other was 4.4 grain. That is pretty small.
I find it to be great on hot rocks. I am able to GB them out which saves digging. The iron audio is great too which saves you from digging steel and iron pieces. Having said that, I still like to didg everything just incase.
What I don't like about the ATG is the silliy connector for the coil and the head phones. I find it very time consuming trying to connect them.
It also is a killer on pennies. There isn't a penny out there that this won't pick up. I find myself passing now on the pennies. Foil makes an erratic scratchy sound, so I passs on that too. The target ID sometimes doesn't give a reading as well.
I use the 5x8 coil. I ordered the sniper coil to hit the bedrock better. Bedrock in my area has lots of ridges, gaps etc and the 5 x8 coil is too big.