I have had excelent results with my rather well used V15 in a Pioneer 1000 linear tracking table into my Heathkit AA-2015 built in decoder. I think that as I learn more aboud CD4 after delving back into it this last year, I would agree with one of the previous posts that what seems to make the most change for the better in the sound is lack of mistracking distortion particularly of the carrier signal. The Shure seems to do an excelet job of tracking high frequency signals, so even if the response is falling off at the carrier frequency, the cartridge is not a particularly low output one anyway, and if the carrier frequency is cleanly tracked and at a level that won't overload the demodulator (another possible benifit of the slightly falling response at that frequency) then you get clean sound, good seperation, etc. I did dial in the carrier level for the lowest stable cd4 indication, then was able to adjust seperation and really get good true 4 channel sound ! It was the best I had ever heard after frustrating attempts back in the days when it was current technology of trying to get actual channel seperation and not have spitting and all kinds of distortion.
Too bad the Shure is not available any more. It is the standard for tracking on stereo discs too.