Planet are you from? a RAID0 MTRON Hard drive setup on a [Dedicated] Hard drive controller will run circles around a raptor setup, I know I've built them myself for stock traders. And the prices on SSDs will go down, just like they did with modern hard drives.
No matter if it's faster or not, I have 2 Firewire 400 ports on my PC, they've never been used. USB is just more readily available. (Also its near impossible to find a mobo with 1394b)