I had the JD100 and loved it as well. I noticed an improvement from tube rolling and from improved isolation. I didn't try different power cords. I have an all-tube system and I thought it had an analog-like tube sound to it. The only reason I sold it was because after I set up an Apple Airport Express, I found myself listening to my wireless music server more out of covenience, and finally, I decided to sell the JD100.
-Mark
-Mark