I have had mine now for a few months and have used it on the beaches of Florida, New Jersey, Maine, and Mass, it works great in salt water with no issues. I also use it on land in parks and for gold prospecting in Alaska.
I have beaten the learning curve by going to this web site.
The tricks to using this unit are simple and I wont be selling mine!
I have also posted some tricks I have learned about this machine on this site. One of the biggest tips is to ballance the frequencies prior to use when going to salt water (this not required everywhere or with all the coils). With 96 of them running this trick has worked everytime and makes this unit extremly quiet on the beach or in salt water. You can read about this trick on the P2P forum, no more noise in the water. This unit has it's tricks if you don't learn them all you end up selling it frustrated and all you have done was waist your money when all you needed was to learn a few tricks. This is no differant than buying the Andy S book on the Quattro and learning what Minelab didn't tell you.
I love mine and would'nt part with it. I have the standard 10x14DD the 5x10DD and the 8"Mono. I use the 8" mono at the beach which is the most sensative coil and may not be the best choice but my frequency balancing has made this coil extremly stable. I use the 5x10"DD for fresh water and parks.