absolutely, I have been using both XLR and RCA ever since day one with NO signal loss. This is one of many great features about SunFire amps. I have tried different amps but you can only use either one at a time, if both XLR and RCA were connected, then you will experience HUGE signal loss almost by 50%. As far as XLR and RCA sound differences with SunFire, it's hardly noticeable, a slight edge would go to XLR.
