I don't think I've ever polished my guitars. I oil the fingerboard of my ESP every now and then but that's it. Of course I wipe them down with an old undershirt but I never use polish. Am I missing out?
I don't do it either. Poly finishes stay pretty bright and I can't see a polishing making much difference; nitro finishes can react with polishes and frankly if you're looking for a bright shiny finish nitro probably isn't for you.