Whenever I had both my 60s and the 80s on the tiled floor of our former TV room I can't say that I remember seeing them leave marks, might be the type of tile.
I do like using the rubber feet on a carpet floor ... for some strange reason the speakers seem to want to lean outward just a little so I found using a quarter or two under the feet on the outside leaning side makes for great shims to level the speakers and the quarters fit nice and snug under the feet. I've never used the spikes ... I'm thinking spikes attached to a 100lb EP600 probably needs OSHA, Good Housekeeping or whomever it may be that does the home safety testing stuff stamp of approval first.
