I do have an opinion on the Esoteric K-3X, since I did own one for awhile. My overall impression of its sound is very detailed and musical, but can be a bit clinical. The sound can be tailored with variable sample rates and digital filters. The disc drive was in No way like a cheap computer disc drive. It's function was solid and inspired confidence. When used as a drive, the analytical sound transferred to the DAC. When used as a DAC, and fed by my reference PS Audio DirectStream transport, the sound was fuller and more analog, very much like my reference Berkeley Alpha Reference 2 DAC. So, as a DAC, I found the Esoteric more musical than what it was used as a CD player or a transport. SACD reproduction was stellar. Very, very close to my reference T+A PDP 3000 HV.
When looking for a one-box CD player, I saw a used Esoteric K-3X at The Music Room, an on-line audio dealer. I think they listed it at $7500?? At this price, Is consider the K-3X a bargain.