Hi Nagg,
I have never used one, and I don't sell a whole lot of them, but I have recieved some feedback from customers that have them that is very positive. I have a customer in Alaska, a commercial salmon fisherman, has a twinscope and says he uses the forward scan running a circular pattern to locate salmon schools. He says nothing else on the market will do that for him.
I have another customer who has the Iscan 180 on his yacht. He cruises between Seattle Washington and southern Alaska and I guess there are alot of tricky channels and submerged hazards. He says the 180 has saved his boat more than once.
I typically sell the Interphase forward looking sonars to people who own larger vessels that cruise unfamiliar waters and look for moorings in protected waters that may contain submerged hazards and tricky narrow channels.
I have read some posts on other sites of people complaining about the speed of the scan. They complain the speed is too slow especially in shallower water where they really need it.
Interphase is a highly respected company with an excellent reputation. You can contact their technical support people who are happy to answer any questions or concerns you may have. Here is their email address.
matt@interphase-tech.com
Good Luck!
Pat Huffman
Fish On Marine Electronics
www.FishOnMarine.net