PCI-e ssd or ssd raid?

The OCZ PCIe SSDs are not that good at all, and get surpassed by a single Intel SSD in terms of random IOps performance, though OCZ gives you high sequential speeds.

There are no real PCI-express SSD controllers; so OCZ uses SATA SSD controllers and a RAID controller to interface with PCI-express. Its a solution inferior to 'the real thing'.

Rendering files are mostly sequential access i would think, so a large RAID of HDDs would be a possibility too.