HD Voice has been great for me as well. I got my wife a G3 when I got mine and everytime I call her we are on HD Voice and the audio quality is much higher than a reg call. I would dare say that audio quality when on HD Voice is so good that it is comparable to that of Skype. I'm loving it.
Have not had any issues hearing anybody or anybody complaining about the way they hear me. No issues with calls, period.