I have the Quattro, and love it. The depth is incredible, and easy to use. If you've used other detectors, pinpointing will take some practice. Also I suggest you read the book "Mastering the Quattro". This will give you lots of good tips, and helped me immensly!
I use mine mainly at the beach in wet sand, and have no regrets buying it. I think for what I use it for and the money, it was the best detector for me.
HH 8) surfrat96