Seems to me that both are Indilinx ASICs? Wonder if they are just slightly downtuned and now the Vector is the highest performing now? I see slightly better specs with the vector and a 5 year rather than 3 year warranty.
OCZ Vector 7mm SSD Low Profile 2.5" SATA 3 6Gb/s SSD
OCZ Vertex 450 7mm SSD 2.5" SATA 3 6Gb/s
OCZ Vector 7mm SSD Low Profile 2.5" SATA 3 6Gb/s SSD
OCZ Vertex 450 7mm SSD 2.5" SATA 3 6Gb/s