I've never used any of those, but I've heard good things about all of them.I prefer a machine with a numerical readout and with that in mind these are some good machines at about the $250 price range, Teknetics Delta 4000, Minelab Xterra 305 and the Garrett Ace 300. If I was buying one in that price range I would definitely check out the Garrett.
My wife has a Bounty Hunter Platinum, it is a great machine and very light weight. They sell for $300.
Probably not very well.Would a mine detector work?