I went through the steps to disable HD voice calls but I still get them from my mom when she calls me (unless I'm on my Bluetooth headphones). I usually only text my friends rather than calling them so maybe if I talked on the phone more I would have this issue with more people.
I hate the HD voice calls! It makes the call louder on the lowest volume setting, which is too loud for me. If my mom has a coughing fit while on the phone with me, I really hear it! It also has a static sound with some words, especially words that have the letter "s" in them. It definitely doesn't live up to the hype of it sounding like a person is in the room next to me talking. I prefer the background noise with regular calls than this feature that makes calls "clearer."