Old thread, but added Puritan Labs a month ago along with Route Master and City Ground Master. I have been grounding to the X1, but today changed to grounding on X1 power supply. I prefer the power supply grounding. X1 grounding seems flatter and less information for me--I did not notice background singers prior on song testing, but with grounding on power supply not only were they present but imaging and soundstage enhanced over grounding to X1. As always, with your system and your take, results may differ.