Billl if you fly a lot line of sight (los) you want the telemetry data on your transmitter, like battery voltage. The rxsr has telemetry function. if you fly more fpv you don't necessarily need telemetry cause you see the data in your osd. in this case you can go with the xm+. The main benefit of the rxsr when flying fpv is: if you add a GPS module you have the coordinates on the transmitter in case of a loss