LOL, that's why we have to try things ourselves, we've all heard a lot of things. So far what I've found is that it all can be true -- depending on the strain you are growing -- some like a lot, some like a little (the person who I was talking with was growing Mephisto strains, if that makes any difference). I also read a comprehensive article that largely went over my head about how all plants need a dark period for certain necessary metabolic processes... on the other hand I've read consistently that autos can thrive under 24/0. So who knows.
I'll hedge my bets next winter (my first auto indoor) and go 20/4, I doubt I'll lose too much growth with 4 hours of darkness and maybe the "rest" will do them good. I suppose that's my answer to most things, some path down the middle. I'm not trying to break any records, I just want them to finish well. I'd rather have a plant that ended at 75% of it's genetic potential, than one that I burnt to a crisp attempting to squeeze 100% out of it.