ace 250 are some coins hiding

A lot of coins and other goodies are masked by iron or other metal trash.

I find that slowing the swing speed down helps, sometimes but not always.

This is what the AT Pro is supposed to overcome, but I am finding it a challenge learning the sounds, because there are so many of them, and what they are attempting to tell me.

My biggest problem has been hot rocks, as in millions of them, and the ground balance feature solves that problem as the AT simply blocks them out, but it does pick up every scrap of iron and foil for sure which is where the challenge comes in learning the sounds and what they mean.

It's all to do with the recovery speed of the particular machine, some are better than others.
Even if a detector has a fast recovery speed, it can still take a keen ear to
determine the target. If in doubt, dig it