I have owned a side kit for years. If you haul coils or a lot of steel, they can be great. It saves time when you don't have to tarp. There are some loads that pay a premium that you can haul in a side kit. Most of the time you save on tarping time. I rarely took my kit down. I have a couple of friends who owned kits and they had them down more than up so they got rid of them.