I used to have a Fireface UFX and liked to couple it with an RME Quadmic preamp which gives you 4 additional preamps.
Perhaps worth mentioning that I sold it due to money issues and later got the much cheaper Focusrite Scarlet 18i6 and I can honestly tell you that except a slight (but practically inaudible) difference in latency, for home recording use I did not notice much of a difference, and certainly not enough to make the Fireface worth the money. Nevertheless, RME makes fantastisk stuff, quality all the way. I kept my Quadmic and still use it.