Why do you need updates? If the units work, why update them?
I am going to add a 360 to the transom. I can link it to council and bow unit. The problem with the 360 on the trolling motor is the motor must be down to use the 360. I usually don't drop the trolling motor until I see if there are fish. With the 360 on the transom I can check the area without spending time dropping the trolling motor and waiting for the unit to fire up, load, and scan. Being on the transom I can deploy while drifting into the area. IF I don't see anything, fire up the main motor and move to the next spot.
As for your question, I would buy the Helix unit.
HOI Crappie Club
Where family and friends come to compete for a little more than bragging rights.
Quick, someone teach me how to fish so I can win this tournament!!!