The Corsair P3's are simply C300's with updated firmware. They have great read speeds (410) but relatively slow write (210) speeds. If ya system is going to have signifcant page file, temp file and scratch file usage, this could be a downer.
The Vertex series has similar read and write speeds. The Vertex 2's are 285 read and 275 write, whereas the Vertex 3's are 550 read and 525 write. Don't expect the Vertex 3's to ship before 2nd quarter tho.