I've had lots of 9v PSUs, including isolated multi-ports one. at the end of the day we all sometimes need just a simple power supply to power a lone pedal. or a Roland electronic percussion. or a Boss vocal looper.
I've directly compared this one with Boss, MXR and Mooer and I liked the noise floor on this one best. Boss was the second, MXR was the worst.
I feel that it somehow filters some noise that's still there, when I plug directly into the amp without my pedals or using a 9v battery in my tuner. it doesn't like completely remove it, but shifts it to be higher pitched and harder to hear. so now I just use those on everything and don't think twice.