This one has come up a few times, and one setting that seems to be consistent with most users is 50% sensitivity.? Anything more seems to pick up every little mineralization, which at first seems like a good thing but after digging a lot of empty holes can be a little annoying.?
Also listen to the machine.? Solid targets (in my limited experience) always give you a nice solid d-ding-d-ding-d-ding, and the id on the meter thusfar has been correct.? If you're into specific coins, really look at the meter as a dime, penny and quarter all sound about the same, but show up slightly different on the display (on their correct symbol, which are right next to each other.)? Single "blips" are generally trash, even down at the nickel level.? Every nickel I have found has given me the solid signal, every pull tab and piece of foil has been a "blip".? The cast iron, cans, keys, bolts, etc. have all also been single blips.?
I have not found any rings or other jewelry yet, but have air tested with some of my wife's stuff ("No, honey, I'm making the bed, I'll be right out!")? and they also give the nice solid d-dings.? This being said, I have found the jewelry setting to be the most friendly, it is set to cover both jewelry and coins and discriminates out the lower trash settings, though at just the right angle you will still get the very occasional piece of foil.
Pinpointing has been deadly and as easy as the manual would suggest.? I have found the target to be directly under the inside of the point of the inner coil, with the depth being pretty darn good as well.

Well, enough jabbering for me. Let us know how it went for you, and get some pics up there!
HH