Thanks for your well expressed clarification, particularly how the 118 by itself keeps the guitar and related transient rich instruments sharp and clear, in contrast to the Christine which has a softening effect. I also like your methodology of recording your own piano playing in your room as a reference point. Actually, I have never been happy about the sound of any piano in a room. Even a 6 foot grand piano needs a room at least the size of a small recital hall to sound its best, free of the stifling affect of nearby walls and low ceiling. In a typical home, the piano is bass heavy in a similar way to how large speakers sound in a tiny room, but much worse. So by doing the recording in your room, you brilliantly correct for this effect. Even with my own listening to a piano in the home, I can still tell that the percussive effect at all freq is tight like a mallet striking an anvil, which is not at all like the woolly mush coming from many tube amps and some euphonic SS amps.
Although I agree that terms like "cool" mean different things to different people, let me propose a simple way to describe what I mean. Compare the sound of a flute, oboe, clarinet playing the same note A 440 Hz at the same volume level. The flute has a "cooler" or "whiter" sound than the oboe or clarinet, possibly due to the fact that its overtone structure is skewed toward higher freq. The 3 instruments all have most of their energy at the fundamental A 440 Hz, but the differences in complete tone are related to different proportions and phases of the higher overtones. The oboe and clarinet sound more similar to each other than to the flute, with the oboe possibly sounding brighter due to the nasal piercing quality of its harmonics. In my vocabulary, cool is like bright with more HF proportion, and warm is like dark with less HF proportion and more bass.