QuickBench helps to illustrate the maximum potential speeds that drives can achieve. It uses easily compressible streams of data, so its results should be read as a best case scenario. All of the Sandforce based drives perform nearly identically. Crucial's m4 pulls off a small win for sequential reads, but is a little slower in the other two tests.
The three Sandforce drives excel in QuickBench's write tests as the data is compressible, a strength of the SF-2281 controller. The Crucial drive with its Marvell based controller doesn't get a speed boost with compressible data, hence slower performance in this test.