I recently purchased the Esoteric K-01 to replace the X-01D2. The K-01 is far superior to the X-01D2. The improvement was easy to detect, no A-B evaluation was necessary. The K-01 sounded extraordinary right out of the box, still cold. It is the best Cd/SACD player I have ever heard. I am trying out the G-orb, which I intend to buy, but its effect is subtle. The K-01 sounds great with or without the G-orb.