Pardon, but I dont see any superb behaviour of the horn implemententation of the JBL monitor. The distortion and the unneveness in frequency response at 96 dB is acceptable, but worse than Genelec 8030c .The horn implementations that JBL typically has are significantly superior. So it's not flat out superior. This is showcased by the incredibly smooth directivity and lack of weird behavior in the highest octave.
Neumann doesn't even bother with horns or extensive waveguiding because they're not targeting the high-end PA world. This speaker is capable of 117 dB / 1m peak output from 80Hz to 20KHz. Something I'm sure the KH150 is not even close to achieving.
At higher levels the horn in jbl will be better ofcourse.