I think I would really like the Helix, but I had to pass on it. They can't be networked with other units which I'd like to have but the deal breaker was that it only took the Micro SD Card. I already have 2 regular SD cards to use and didn't want to spend almost $300 to buy the Micro SD cards....So I went with the Humminbird 859 DI for the front of the boat and the smaller 688 DI for the console. I can network these 2 units and still use my SD cards that I already have. Thx for all the input.