One thing that I guess is a potential problem is the quality of the records being used. If some records are noisy primarily due to surface oil and debris and others are noisy because of groove damage and surface scratches, then obviously the cleaning results will be much different, at no fault of the cleaner. I see that they were planning to do a "before and after" recording, but that won't tell the story as to what caused the noise, damage or debris. Still, I suppose an assumption can be made that the records' surfaces are in fairly equal condition and go from there.