I agree with gsHarmony, I got the FF800 this weekend, very easy to set up, the software to control the routing is way better than firestudio. I recorded about 15 hours this weekend and never had a single problem.
Its not that the firestudio can't be used, I eventually did get it to work, but there would be random crashes. For example when I adjusted the zoom on the tracks it would freeze up. When loading some vst instruments it would crash. Unfortunately I can't return it, but I can still use it as preamps through ADAT running the RME as the master.
FF800 is definately worth the extra money in comparison to firestudio.
Good luck