Depends on what is one using machine for. For home, cleaning a few records a day - almost anything will do. With little more or little less hassle.
If you are faced with say 100 LPs daily, both sides at once machines do make sense. As does the quietness of the vacuum part of the machine - it is not loud from the perspective of onlooking visitor/friend/customer, but for the operator it does get pretty noisy. Please bear in mind not all records can be vacuum cleaned in a single "pass" - there will be always some spots on record that for some reason do not "wet" properly and require repeated or prolonged contact with cleaning solution - MUCH prolonging the time needed with normal records. You have to continously watch the surface of the record on the RCM in order to spot any such problems - requiring you to be quite close to the RCM.
I realize it's still a process I just like the idea if not having to fiddle with brushes.