I have raptor raid.
No fps increase, as df don't acces disk during game. Save are insanely fast, but it doesn't really matter. (but other games load times are blazing fast and that does matter)
Almost forgot: don't do raptor raid. The noise.. Oh God the noise.
The game might not, but don't forget about those 3 dozen OS services. Some folks like to monitor their monitoring programs, too, while playing. Never could reason that... All that stuff writes to the HD, at some point in time, possibly while your playing DF, it'll wanna Defrag, who knows!?! These things have a mind of their own nowadays.
Performance RAID-0? No recovery. No fear. Is that how your setup?
They do sound like miniature 747s on the runway, don't they? Rawr!
I don't notice it anymore, since sticking them in this case. Gotta love turning the case into a heat sink. Then ya don't need as much vents. Or a blow hole for that nasty noise to come out from. So many cases are plastic. Alienware is plastic. Hate that junk, it hardly does what its supposed to. Raptors do complain, from time to time, especially at bootup. Without the sides on, it is loud, definately a good warning to be considered.
However, sound can be dampened with a couple dish sponges, for less than $5 dollars. I've had noisier vid card fans. Isn't it awful when a ball bearing rots? I think it has something to do with whether the drives are compressed or not, to be honest, not in the maker or the model. But hell I dunno. I'm still fearing my capacitors will explode.
http://en.wikipedia.org/wiki/Capacitor_plagueKnutor