Is the SI on Helix "better" than the 898? I realize that I am talking about a 10" screen (for the HD transducer which my 898 already has) compared to a 7" screen on the 898. I already have an 898 SI on my boat. I'm going to buy a Helix, mostly for the Auto Chart Live function, I just can't make up my mind whether to spend the extra $ on a SI unit. If I knew that the Helix SI would potentially draw better pictures and show more detail than the 898, I'd spend the extra money. I played with some display Helix units in simulation mode, but without the core unit(which they didn't have) right beside the Helix, it's hard to tell much about the differences. Also, does a Helix DI have better DI than a SI unit? Thanks in advance for your input.