I almost always reply to vm's. I mostly do because of the left out feeling I get when people don't reply to mine. I don't like other people feeling like that, so I reply to most of my voice messages. The rare times where I don't reply to voice messages deal with messages that I'm not sure how to reply to or I'm too busy with requests or something. D:
Ohhhh, shoot. I forgot the rest of the post! I reply to people's vm's most of the time, as do people for me. However, just as I don't reply to people sometimes, people don't reply to my voice messages either. Annnnnd, as I also stated, it hurts my feelings occasionally. I know it doesn't matter, but whateverrr. :]