I'm not an expert on this, only my limited experience and opinion. I believe a rattle can job can look decent, but it seems to be difficult to get a consistent sheen with a gloss paint across an extended surface. Also, I think the "wear-ability" of the rattle can paint is less than a regular paint job. I know the few paint jobs I have done, all the paints have a hardener component (clear-coat). For me, I wanted to learn how to paint. So I went through several paint systems (HVLP - turbine, HVLP-compressor, and plain compressor gun). Not because I wanted to, but eventually the normal gun driven by a compressor worked best for me (orange peel issues). I found it very frustrating, but rewarding when I finally got it to work. Again, I'm not an expert, but a least I learned something and feel I could do a decent job on my next project. It seems like running boards would be a perfect project to learn on if you are so inclined. I think you would end up with a better job and an enhanced skill set.
