Well, it all depends.
First, with your power failing, there is no way to retrieve your quad other than by searching. All those methods depend on some power supply. So in your case it would still be lost. That is why I set the failsafe to throttle cut. That way if I lose control, I can switch the tx off and hope it drops not too far away.
Actually for your scenario I do not think that you need to switch to a Taranis. The FrSky GPS module has very limited use, as you can only transmit tha data to the tx log. This is useful, because even after a power fail, you will have the last position of your quadcopter. Yet, for FPV with OSD I would go for a Revo with Revo GPS. Those GPS data can be transmitted to your GCS or the upcoming Android app as well, and are much more useful that way.
So, I would go for the classical lost plane alarm, and a revo with GPS.