I have the Helix 8 Mega SI+ and Mega DI+ and switch it from bow and stern depending on where I fish. I only have SI+ at the stern where the SI+ transducer is mounted....I use the Mega DI+ transducer when it's on the front that's built into the trolling motor.

Mega DI+ is AWESOME!

I'll add another unit eventually and then link with ethernet so I can access both transducers from the front, but for now I'm satisfied with what I've got.