I have used the Babyface with the Presonus Digimax FS 8 channel ADAT interface many times for live performances. Rock solid with buffer set to 128.
HOWEVER, its generally accepted to never run a computer audio interface directly into a PA system - always into a mixer first. That way if there is a crash or a MIDI malfunction for any reason and there is loud unstoppable noise coming from the computer audio interface, you can always turn it down at the mixer.
Brontoy