The 3.7 is not bright. If somebody finds it bright it's because they
have bright electronics, a bright room and/or prefer a rolled off
sound.
I agree. The Soundstage measurements of the CS2.4, for example, show an exceptionally flat response, +/- 2 dB from ~33 - 20k Hz. I think that is the best in their data base (you can ignore Stereophile's measurements which are taken at a mere 50"). Subjectively, I hear a very neutral presentation from the lows to mids to highs that corresponds to those measurements.