I also use this plan. So far its been great.... However VoIP calling on a Nexus 4 is horrible. I believe this a codec issue? I just end up buying extra credits

I also use this plan. So far its been great.... However VoIP calling on a Nexus 4 is horrible. I believe this a codec issue? I just end up buying extra credits when I go over. Even with that it's been significant savings.