SPin drain, neutral drain
I'm with John combo on this one, my spinout 70's Filter Flo and Maytag send tons of dirty water right through the clothes while spinning, no difference at all from a neutral drain, just sideways residue on clothes instead of straight down residue. My Whirlpool does the neutral drain, I have never seen any difference in results at all. If any of the machines has a worst-ever nasty load, then the filter helps a lot but at times (rare) I just put it back through a second rinse and all is well. As far as I can see, Whirlpool and Filter Flo are both aggressive and the Maytag is gentler, but neutral versus spin drain makes no difference in my wash.
Just my 2 cents...
However, I still hope to someday find a good EARLY automatic where there's an overflow rinse, and/or a solid tub where the spinout goes out into the entire cabinet. As fun and reliable as my 70's Maytag and GE and 60 Whirlpool are, I still hope to find a far rarer and older machine with very different technologies, just for fun and uniqueness.....something totally devoted to and designed in the soap era, not detergent. The only overflow rinse I have ever seen is videos here, never in real life, let alone in my basement. I'll keep looking.