coho, I dont have experience with king. The units Ive seen look fine. I think its important to get the right trailer for the boat. I have an eZ loader.

I think the companies build frames to fit a bracket of boats. Where you run into trouble is buying too little trailer for the boat you have. If for instance, you have a short parking area and need a hinged tongue, not all the trailer tongues are thick enough to support a hinge.

Some boats could be put on a single axle trailer, while a dual is really the better choice. I suspect the brakes option is a important consideration.

Similar considerations that are used when buying the right truck for the job.