In my experience in the Galaxy radios I tried it in (959/979) it didn't really make any measurable difference. Honestly I wouldn't bother with them again. In certain radios with certain circuits set up in a certain manner I'm sure they can serve a purpose but in most cases I don't think the time/money benefit for most people is going to provide the results they are seeking.
I think part of the problem is that the way these are advertised people are expecting big things out of them (example of the difference between a cheap stock microphone and adding a D104) but in reality the job it performs (or is advertised to perform) is to prevent the squaring of the waveform and provide leveling of the audio so that the results are going to be much less distinct than one might expect.
I think part of the problem is that the way these are advertised people are expecting big things out of them (example of the difference between a cheap stock microphone and adding a D104) but in reality the job it performs (or is advertised to perform) is to prevent the squaring of the waveform and provide leveling of the audio so that the results are going to be much less distinct than one might expect.