[Penthode]

The assymetrical wide band quadrature demodulator would provide better chroma detail at the expense of quadrature crosstalk. Because the crosstalk would occur at the higher chroma frequencies (where the lower I and Q sidebands are present) the effect would be strange colors in fine detail and at horizontal transitions. I recall an excellent article on quadrature crosstalk in an early sixties RCA Review. I will look for it.

The crude use of passive tuned filters made utilization of the capabilities of proper I Q demodulation impractical until more sophisticated hardware became available in the 1990s.

It is curious that the NTSC were aware of the problems in 1952 hence trying to circumvent it by using Phase Alternate Line and Phase Alternate Field demodulation techniques.

It is also more amazing that the British chose an 8MHz channel for 625 broadcasting in the early sixties to accommodate full double sideband R-Y and B-Y quadrature demodulation NTSC in 1966 before making only the last moment move to PAL to fall in line with most of Europe.