They are always a good idea, but keep in mind if you don't have hydraulic tilt and trim you need to make sure it is secured to the motor and trailer so it does not come off when you hit a bump. I only use the type that goes from the lower unit to the trailer. In my opinion the lock n haul and other types like it are of no use whatsoever. If you think about it the purpose of a transom saver is just that, to save the transom from the effects of the motor bouncing. When using the standard transom saver you triangulate the motor, trailer, and boat so there is no stress on the transom. With a lock n haul type all you do is protect your tilt and trim. It does not help your transom because the motor still bounces on the transom when going down the road. And before anyone says something, there is resistance when in the water to cushion the motor, there is not when on the trailer.
2003 Ranger 521VX 35th Anniversary 250 Yamaha
1979 Ranger 168V 140 Evinrude - Papa Smurf