This is a difficult question to answer because of the number of releases this album has seen. Very generally, with the exception of the Columbia Jazz Masterpieces version, almost all of the digital versions sound pretty good and have something going for them.
There are afaik four stereo mixes of Kind of Blue available - (although there are many different masters made from these four mixes). The original Townsend mix from 1959, the direct to digital version for the Mastersound disc in 1992 (this was the first speed-corrected version made from the 'backup' tapes that were working properly), the 1997 mix that was done from these same 'backup' tapes to a modern two-track tape before transfer to digital, plus the Classic records 45rpm edition that was mastered in all analogue from those 1997 tapes.
The 1997 edition, which is the most commonly available in the stores today (and from which all post-97 releases have been based upon) was done as a 'flat' transfer, with no EQ adjustment, and has a lot of good qualities going for it - including being very 'up front' and engaging. It does however, to some ears (and in my opinion, somewhat depending on equipment) sound quite strident in some places. Davis' trumpet can be hard to listen to on some passages. For this reason, many versions have the top end rolled off. This also has the advantage of reducing the hiss that is omni-present in this version. The also-currently available 2-disc Legacy version uses this same mix, but is mastered differently, being a bit warmer with some of that stridency reduced. This is probably a safe bet if you are turned off by my description of the '97 sound.
The 1992 Mastersound direct to digital edition should have been, in many ways, the holy grail, but for whatever reason, it's not a favorite among many people. It has a hiss that is sometimes described as very digital sounding, and has the widest stereo spread of all the releases I've heard. In many places it is far too laid back. On the other hand, this is a version that I can really get in to if I just listen and forget everything else.
One other option that is really nice is the original mono version, of which there is no CD available, but there is a very nice 24/96 version easily available. This was done directly in the studio in 1959 and since the original tapes are missing, it hasn't had the opportunity to be fooled with the way the stereo version has. It can be disconcerting at first since we are so used to the stereo spread, but the sound is very smooth and laid back, with no hint of the stridency that plagues many of the digital mixes. For those bothered by the faux-echo of the stereo version, the mono makes for a nice listen.
Not sure I cleared anything up for you, but, well, there you go!
I find that mastering to be ok on my Woo feeding my D7000's, but pretty grating at times on almost anything else (including my Senn 580's to my surprise).
