Aftermarket Panels in general are thinner metal and made with alot lower quality all around. The aftermarket companys buy up the used stamps from ford and sometimes even other companys after they are too worn down to produce the quality products. They use cheaper steel and also primers ( which is why they rust much faster). If u want a replacement panel that is going to last with minimal work your best off getting a nice shape used gate because it has all the factory coatings already on it on top of the fact that it will fit much better. Although a lil extra work and money spent on the aftermarket panel will help it last as well. First thing, anywhere u can find a hole to get inside the gate, spray lots of undercoating to help seal up the inside, do this before it gets any kind of water inside it. Next off, use a decent epoxy primer on the outside of the gate before u prime it with anything else or paint it, this will help compensate for the piss-poor "e-coating" they apply at the factory. As far as extra support for loading and unloading well, reinforcing is the best option, if u drill holes for screws use some paint to coat the hole to try and put some protection back on. Hope any of this helps ya