The KM 84 is a classic, and to my ears, definitely more real sounding than the KM 140 or 184.
By the way, I've measured numerous examples of this microphone type and can tell you that Neumann's maximum SPL specification of 120 dB for this model was quite conservative. The 0.5% THD point doesn't actually occur until 125 dB or so--and even above that point, the rise in distortion remains gradual for a while. I confirmed that with Martin Schneider at Neumann.
It's not that I think you should be spending your time where anything is that loud, but the microphone can handle it, is the point.
--best regards