pensfan1
I have that same unit. I never use the SI/DI. My next one will have GPS and Sonar only.
It was a Christmas present from my wife and son. Replaces my 561 black & white w/GPS, which when and if I scrape up the jing for a front trolling motor, I'm gonna mount the 561 up front. I do like seein' in color though, (once I get it figured out).
I can even screw that one up what with the GPS, waypoints, split screen, etc. At least both can tell me how fast I'm goin'.