Since stereo reproduction is a psychoacoustical phenomenon, I tend to move forward and back by around a foot while listening depending on the recording. My thought is that the perceived soundstage for any given recording is dictated by the person who was originally twiddling the knobs, and that individual's setup (distance from monitors, toe-in angle, nature of control room acoustic, their hearing and personal taste) all have an effect as to how and where the soundstage unfolds upon reproduction.
For a point of reference however, I tend to use a mono recording to 'set' where the listening distance ought to be for my room and system, other times I'll use pink noise.
Either way, a good system (and room) should be able to present a satisfying presentation without necessitating the proverbial "head in a vice". Just a thought.