It's cool technology, but I think it's overhyped for what we do. Unless you put these transducers on a turret system you will only be monitoring a few downriggers. Lets say a typical spread is 2 riggers, 2 divers, and 2 junk lines. You're spending a lot of money to see what fish are doing in 33% of your spread. When you go to a boat who is running 3 riggers, 4 divers, and 3 junk lines now you're looking at 30% of your spread. My honest opinion is if you have the money to spend it may help you understand fish behavior day to day. Other than that it's a novelty item. However, I have heard what chowder mentioned above where it will show fish in your spread the traditional transducer isn't showing.
That being said, if you want to splurge the PS30 is the way to go on the transom. I sell a lot of them, so reach out if you want one.