It sounds so good, especially for a 1973 recording. In my tippity-top favorites for a perfect balance of dynamics, fidelity, surround, music, and sheer faithfulness in a very adventuress way.
My two favorite King Crimson surround mixes are "Larks Tongues in Aspic" and "THRAK", and the main reason why I think both of them work better in surround than they do in stereo is because of the double percussive elements. (Bruford-Muir on Larks and Bruford-Mastelotto on THRAK)
The sound gets too cluttered at times in stereo, while the surround gives everything its space.
The weird percussive antics of Jamie Muir work particularly well on the surround mix of Larks'