I put on the spring loaded trolling plate on my 115 optimax it did a nice job off slowing the trolling speed but took away from the hole shot and top end over a long period of time spent trolling the motor would carbon up. I solved these problems by buying a kicker and am much happier
When I want to slow down, I point my bow mount trolling motor towards the back of the boat and use it to slow the forward speed of my 115 hp. Works great, and you can steer with either motor.
I had one put on and it took ~2 to 3 mph off top end speed of my 50 hp yamaha; with a bigger motor might take even more off. Also, slower to get on plane.
Was hard to turn the boat with the plate down as well.
It also added a few inches (maybe not a huge deal) to the overall length of your boat when you store it the garage.
When I want to slow down, I point my bow mount trolling motor towards the back of the boat and use it to slow the forward speed of my 115 hp. Works great, and you can steer with either motor.
I’ve been doing this for over a year now and it works fantastic. Even if I had a kicker I’d use it as a keel in the front of the boat for better control in the wind.
Drift sock or trolling sock is a better option in my opinion. It will slow you down with better control. And then fine tune it with the bowmount if you have one.