It looks like Corsair did some magic tweaks to the Marvell controller's firmware, as their Performance Pro 256 GB is the fastest SSD we tested so far. It even beats big-name Sandforce SF-228x drives like the Kingston HyperX 240 GB and OCZ Vertex 3 240 GB. We suspect that Corsair did something unique to their drive, because Crucial's M4, which uses the same controller, and should thus deliver very similar performance, ended up being 10% slower than the Corsair Performance Pro.
In terms of price/performance the drive easily claims a leading spot, despite its $400 price mark. When it comes to GB per Dollar, things are not looking so great. You can find some high-performance Sandforce SF-2281 240 GB drives at well below $350, so it wouldn't hurt if Corsair adjusted their price to something like $375 or below.