Hmm. I had thought the performance of the smaller Samsung controller drives to be significantly worse than the equivalent sized Indilinx controller drives but it appears the review I was looking at was wrong. I've worked out what is going on with the listed speeds and prices. The review is comparing the 256GB P series against the 128GB S series.

The Corsair drive uses the new Samsung controller + 128MB cache and is quite a bit cheaper than the Vertex drive and similar in overall performance.