I got one this past summer for my SUV17 since I cant trailer with the motor fully down without scraping on driveway aprons and such. I wish I had bought one earlier. My wife was following me in a separate vehicle on our vacation and said the motor was jumping all over the place every time we hit a bump. It doesn't move at all now. I really don't know if its entirely necessary to protect the transom (there was a previous thread on this site about this topic) but all that jerking around cant be good for the motor.
I have used transom savers on all my boats for many years. And had one on my skiff too. However, I have recently changed over to these devices on both my skiff and my bay boat and will never go back. Work way better.
I have the universal wedge and centering clips on my skiff and the Yamaha brand on my bay boat.