Minelab GP 3000

Hi All,
This is for prospectors who used and owned this machine:
What is one of the most important things/features on this machine?
What did you do to make most of this machine?
What would be the most suitable coil to use with it?
What was depth of your gold find?
Which gold bearing ground you like the most using this machine?
Thanks

I had a GP extreme. does that count in this post.

but i found the best coil was the 14x9 coiltek