This Koetsu and Jan Alberts threads are very interesting. I was able to home audition a store's demos of the Koestu U, RSP and OP in my system and in a friend's before deciding to buy the OP. We both have Graham 2.0 deluxe's so we had the cartridges on separate ceramic wands. He has a level 5 Audio Note/Avante Garde Trio system and I have the Aesthetix, Audio Note and Wislon W/P system. They are both fully tweaked reference systems in excellent listening environments. Each system does have different qualities. We each preferred (and purchased) OP because it demonstrated a faster, more delicate, less noise, and a greater sense of space around the instruments while still having all the musical qualities we were expecting in each of our systems. I was surprised that the OP's sound qualities would be so apparent in two radically different speaker systems, but it was for us. He loads it at 3 ohms by his AN M& Silver Transfer and I have it set up at 10 Ohms in the Aesthetix. Some times I go to 100 ohms, but I seem to prefer the 10 Ohms load. BTW: so now I have four arm wands and have sunk a lot of money in cartridges over twenty years. It one of the easily addictive aspects of audiophilia obsessiveness. I should have two-thirds of that money into real estate.