We are clearly using language differently. What I mean by seeing Saturn's rings distinctly does not occur at 18x, but (in my 82mm scope for example) somewhere near 50x, as any number of sources generally attest (e.g.
Sky & Telescope). Perhaps some people can detect the first bit of separation on a good night in an 18x70, but I don't find that terribly satisfying myself, and Roger couldn't, so that's not why he preferred them over the SLC. (He does say he wasn't using a tripod, which seems odd.)