Just to let you know, my goal has always been to get as close to the recording as possible, never to "color" this with warmth or anything else. The entire decision to go with active crossovers and 10 channels of amps to drive speaker drivers directly is to remove any and all distortion.
In a lot of the comparisons I made I listened for naturalness in vocals, realism in piano (jazz and classical), horns (tenor sax in particular), and reproduction of acoustic bass.
My bias is definitely towards neutral, but I would describe it as realism. I always do a comparison with music playing and me listening in another room as well. I find this really helps discern realistic playback.