I get that it's very cool to be able to call over wifi rather then burning minutes, and that's why I'm giving Hangouts a third (yes, a third) try. But an app that works just like SMS, and integrates SMS into it's functionality, plus some proprietary layer that only allows you to access those who have also installed the app? No thanks. If I have to communicate using text, I'm sticking with email until they kill the idea. It's anywhere, everywhere, and platform agnostic. Google has done a lot of amazing things, and will most likely continue to do them, but I'm not giving up something that I know works if the alternative isn't going to cut it.