Been looking into the SI/DI really hard the last few months myself. I think the for me the DI will be more useful, that is until I learn how to read the SI. I got a chance at Talquin to view it and try to understand what it is showing. Pretty useful info. I know alot of folks are using DI/SI to scout water before even wetting the hook and making it payoff. It is expensive, but when I can I will most likely end up with and 898 HD on the console and a 788 ci HD DI on the bow. The 500 series is available with HD DI but has limits on software and linking to other units. The 700/800 or higher series allow the linking from what I have found so far.
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