Oh, wow. You are going to get a lot of opinions on this one.
Specifically, are you asking us about repairing one or using one---- or both?
Like most machines of that era they had their drawbacks.
Small capacity by today's standards. An 8 lb load instead of 18.
It took careful loading and as short a Wash cycle as you could get away with, to keep from getting a tangled mess. One became rather skillful after a while.
In 1956 Frigidaire added the Three-Ring Detergent Column. IMO this was kind of gimmicky. I think the Circulator Ring was supposed to slow the rollover a bit to reduce tangling. I feel as though it creates a lot of extra splashing that disrupts the wave the Lint Remover ring should make on the down-stroke, and stirs up a lot of extra suds.
They were great for people who did not own a clothes dryer----- which was most Americans during the Unimatic era, due to the 1140 rpm spin.
Some people had serious vibration problems especially on wooden floors. I never had that issue although I have used many a Unimatic on various wooden floors over the years. Frigidaire actually sold special wide shoes to put over the feet.
Anything less than a full load invited an unbalanced shut down. You had to redistribute the load then restart the machine. An annoyance, however, most other brands in those days were the same way.
Like most busy households, you had to do the wash when people weren't trying to shower or flush toilets because of the Timed Fill. Just one toilet flushed could cause a fill of less than a tub full of water.
You could usually do a full load in about 25 min. Which was pretty good.
IMO best towel and underwear washers ever. Also, in hot weather, casual clothing such as t-shirts and short pants did very well. I saw people stuff them with everything from jeans to Keds and usually everything came out clean.
Just a few observations.