I've long used Facetime Audio to make phone calls to other iPhone users. Facetime Audio call quality is noticeably superior to cellular-only calls (including HDvoice or voLTE). Much clearer, cleaner audio, better sound range, and less noise. And it is less intrusive than requesting a Facetime video call, especially to people you may not know as well, or at odd hours. Wifi calling generally is terrible -- too much lag, too much noise, lots of audio cutouts/dropping. I've sworn off wifi calling, because it sucks. But I really love Facetime Audio. Apple really got it right. So much so that I now dislike calling mobile users who don't have it. Anyone else devoted fans of Facetime Audio for their voice calls? Also, with the release of iPhone 7, a couple people I've called are new to iPhone and IOS (they switched from Note/Android). When I called them using Facetime, using audio only, this must have been their first time getting such a call. They asked me, "what's this? Why is my screen black and what is Facetime Audio?" They both noted the calls sounded superior to their regular cellular calls, and now they are using it as well. So just wanted to see if anyone else is a devoted Facetime Audio fan. Finally, if you want to know how to use Facetime Audio, it's very easy and there are lots of online resources about it. There are multiple ways to access it. You can click on the Facetime app, select the "audio" toggle at top, put in your contact, and if the contact is blue, you can make a Facetime Audio call to them - just press the phone handset button. If you press the camera, it will initiate both audio and visual Facetime. (Contacts who aren't Facetime-capable are greyed out.) Alternatively, in your Contacts book, if your friend, acquaintance, or contact has a Facetime Audio-capable device, Contacts will automatically throw in a line entry that says "Facetime," and on the same line of text you'll see symbols for video and a phone handset for audio -- select the phone handset, and it will initiate a Facetime Audio call. You can even put down Facetime Audio as your "Favorite" under the Phone App, for one-button dialing. Anyway, here is one article among many discussing why Facetime Audio is the way to go for your calls, especially to people you may not feel comfortable being on video with.