The Roto-Flex did have one drawback.
Gordon, in my past experience with the Roto-Flex agitator, was in the 1968 800 model 3 speed alphabet washer my parents had. Now I give credit where the credit is due, this agitator did good in cleaning the clothes. A lot better than most of these new machines today. However, if you used the lower water levels, sometimes a button would get caught under a fin, and would either scratch the finish on the basket, or it pull the button off completely. To solve this, I used the highest water setting, and this worked until I had to replace it with a Rotoswirl.
Again I will say that they are much better than what they make today, and if I was restoring a machine that originaly came with a Roto-Flex, absolutely I wouldn't change it if I could help it. I would do my best to keep the integrity of the machine. Have a nice day.