I've had Unimatics, Multimatics, Pulsamatics, Roller-Matics and 1/18's come and go in my collection, but by far the best is the Unimatic in my opinion. Clothes are clean, properly rinsed and totally spun dry and it only uses about 27-28 gallons of water. To top it all the Unimatics put on the best show as they are the most dramatic of all the Frigidaire washers (again IMO) and of course that is what is most important in rating a washer.
I did not keep any of the Multimatics, Rollermatics or 1/18 and passed those on to other collectors. I have five Unimatics hooked up and running in the collection (1947, 1952, 1955, 1957 and 1958) which I use all the time. By far the 1958 WCI-58 is my workhorse washer and gets used more than any other washer in my collection. I also have two Pulsamatics (1955 and 1957) hooked up and running because they are such fun washers as well.