No, not the one in your bathroom…!
After writing this post about the Vivitar 500mm f/6.3 Mirror Lens, and having a bit of time on my hands to do more DSLR + Mirror research, I came across a few more reviews:
Olympuszuiko site, with images.
Pro Optic 500mm f/8 for the Sony Alpha, with images.
Rokinon 500mm f/6.3 on a Pentax, with images.
Mark Sabatella The Vivitar 500/8 Mirror Lens
Popular Photography CAT Article (2003!)