Rustoleum vs. POR 15 vs. others

I could be slam wrong on this.....but my understanding of POR15 and similar agents is that they are NOT rust converters. They are rust SEALERS. They do not change the chemical makup of rust, they simply seal it from air. Once sealed from air, rust can no longer spread. I have used POR15 before with great results. You do have to top coat it, but who wouldn't do that anyway? I wouldn't want the POR15 to be the top coat, regardless of its ability to withstand UV rays or not. Also, the way I have always done it, was to do all necessary bodywork first to the bare metal and then coat with POR15. It has always worked well for me. It is true though, that you better be ready to use ALL of whatever size container you open, because it does not keep well even when following the instructions. Other than that, I have found that it works as advertised.