Topic: UFX question

Hello I have question about the best way to link a macpro with an UFX fireface interface. I use to have an ADI 8DS with RME Adat card and it was sooo much smoother than using firewire on Fireface 400: better latency, less cpu.
Is it the same with UFX ? shall I buy Raydat card or use firewire 800 ?
thank you