OK, I am wanting to upgrade my bow depth finder. I have a terrova ipilot and and 898 si (non HD) on the console with a lakemaster card. Is it worth the extra money for si on the trolling motor. I want to be able to link everything up and be able to to use follow the contour from up front. To be honest I dont really use the si on the console as much as I should because I spend 90% of my time up front. Do you think I would use the si more on troller if I had it. Last but not least there is a 150 rebate on 858c right now for bass pro, gander. cabelas, so is the extra money worth it for a 900 series. I have always said go bigger but on just di will it make that much difference thanks.