I have strong preference of using VoWiFI rather than other VoIP types (Matrix, SIP, whatever) because of the following reasons:
- my carrier plan has flat rates to landlines and to all other mobile carriers in my country
- I’m living very close to the border (couple of hundred meters) and my carrier’s signal is really bad in my apartment. I’d really really benefit from VoWiFi because it would mean a better call quality and no dropping signals and/or calls. People could reach me without using an extra client or number. They’d just need one number from me and would always reach me on the same device.