I'd have to say the early Unimatic agitator winds hands down. I played with the 3-ring at the Convention, but didn't get "up close and personal" with the WI-57, WCI-58, and WCI-59 to test the cleaning ability of that one.
My WO-65-2 with the 2-ring agitator is EXTREMELY gentle, yet cleans wonderfully. The surging currents of the pulsator are what gets clothes clean at the bottom...the ring(s) help with turnover. With an average load, the pulsator gets the clothes rolling and while the upper ring adds entertainment by smacking the water and creating that famous Frigidaire "2-ring wave" at the top, it doesn't do anything at all. On a bigger load it does help though. Correct me if I'm wrong, but my reasoning is that the Live-Water Action constantly submerges and moves the laundry through the water, as well as forces water into the laundry. No article will stay untouched in a "ringed" Frigidaire, that's for sure! The downside is severe tangling if improperly loaded...that's why you always divide the load into quarters. Never load in a circle, wrapping clothes, sheets, towels, etc. around the pulsator like you would with an oscillating-agitator machine!
The "coned" Frigidaires are different. The cones were meant to pull the clothes down, causing slower turnover to curb the tangling that plagued the previous machines. For these agitators to work effectively, however, you have to LOAD THEM FULL. Greg was telling me this is where CR had trouble in testing the solid-tub Rollermatics...they weren't packing the 12 lb. tub like it was intended and giving it low marks on capacity. Unlike the "ringed" machines which roll pretty much any size load, the solid-tub Rollermatic and the 1-18 have much better turnover when you wash a full load in them. Use too high a water level on the 1-18 and turnover slows down considerably to the point of halting completely. They're not as gentle as the rings, IMHO, but still gentler than an oscillating agitator. Let them wash too long, however, and your clothes turn into a big wad of lint (like Jon did...;-) )!!!
That's my view on the Frigidaire agitators!
--Austin