I have the 2010 Mac Pro @ 3.33GHz. Going from the WD Caviar Black that it ships with to two SATA SSDs (60GB each, one for Boot and one for Apps) and one PCI SSD

I have the 2010 Mac Pro @ 3.33GHz. Going from the WD Caviar Black that it ships with to two SATA SSDs (60GB each, one for Boot and one for Apps) and one PCI SSD (120GB, for scratch work) has been unbelievable. This was a fast computer to begin with, but now I literally never find an application waiting on the disk. Xcode builds that take several minutes on my laptop (copying lots of resources into the bundle, for example) complete in seconds on the new machine. Highly recommended.