There are two products I have been using for my Mercury Pro XS during the past few months that I have really come to appreciate. Both have been really easy to use and protect my engine as I trailer back and forth to the lake. The products I am talking about are from a company called Raveling Outdoors and are the M-Y Wedge and Centering Clips.
The M-Y Wedge was something I looked into after using the standard transom saver for a few weeks. This was a brand new boat, but I could already see the rubber starting to wear on the transom saver. I did some research and found that many prefer something other than the typical transom saver since they sometimes cause problem with lower units after wear and tear from trailering.
After talking with some of my friends they mentioned getting a transom saver like the M-Y Wedge. One of my friends had one that was included with his Yamaha when he got the engine new. In fact, Raveling Outdoors makes them for Yamaha. This should say something about the quality and effectiveness of the product.
The centering clips are also very easy to use. You can see in my video below just how easy it is. They help to prevent the engine from moving side to side on outboards with dual hydraulic steering. Check them out at M-YWedge.com