I bought a Pocket Uniprobe from David of Dixie detectors 18 months back. It was $269 US. They are supposed to be the deepest seeking ones. At it best I hit a $2 coin at 4 inches, but only just hit it. Normally 3 inches is it's reach. It's a fragile unit though, due to a weak centre connector of the coil (probe) to the main body, similar to a CB radio. It doesn't like side ways pressure on it, which is what happens to it, if you mount it on your waist. Personally, I'd go for the Vibraphone 570. It is claimed to reach about 3 inches, an inch more than the older 560.
In the September 2006 edition of Gem and Treasure mag, BT field tested a Tesoro Treasure mate, when he did a field test of the Vaquero. If you ask him real nice
he might be able to give you some input on it.
Personally, it will make hunting with the X-Terra a lot easier. I prefer not to use one if I can, but with the X-Terra, it just saves a lot of time and frustration.
Mick Evans.
P.S. When the centre connector broke, I spoke with David, and frankly, the guy couldn't do enough for me. He was fantastic; even though I was half way around the world. I can highly recommend him to you. He is also, a forum sponsor!