Unfortunately I have the original CDs not to compare, but the sound quality of CDs Box is absolutely outstanding !!! Therefore, it is understandable that you would have had little scope for improvements in a remastering here. Mention may be made, the tonal balance of instruments that never dominating piano, the tight bass and the ECM typically airy percussion. I have very many plates of Keith Jarrett, but esp. The Standards Vol. 1 & 2 and prism of the changes are unchanged from the best of what the trio has made.
Conclusion: If you do not have the CDs, these moments of Piano Jazz can earn here cheap.