I was just curious if there was a default or best setting and what changes when you switch from In to Out?
When evaluating which position is correct I always listen to the bass frequencies and the imaging and soundfield depth. I find that when in correct phase the bass is natural sounding, and the images (espcially center images) are located where they sound natural and are more clearly delineated. Sometimes part of the recording is in phase and part out and it’s hard to tell which position to leave the switch in. My general rule: if it sounds good, it is good. So I leave it where it sounds good.
There are some series of discs that I find are generally mastered and released out of phase, for example most of the Japanese RVG series from Japan, and many of the US 96/24 Verve jazz cds. Odd.