I haven't been in love with GVoice since I degoogled my designated "mobile phone" (I've just been limping along without being able to respond to texts on the go), but haven't taken the leap to Voip.ms or Flowroute, due to the reputation problem (eg many banks' snake oil authentications reject "voip" numbers).
My tentative plan is to move my main longstanding "main number" to one of those VOIP providers, and move snake oil auths to either the SIM card in my "mobile phone", a separate SIM on a fixed cell modem, or perhaps just a new GVoice number (which only needs to receive, so interop is easy by forwarding to email).