That review was made before the Vertex 2 came out so the author is referring to the Vertex 1 with the Indilinx controller. He must be getting confused somewhere along the line if he thinks that the Vertex 1 performance is better than the X25-M. Steady state performance differences between the Vertex 2 and X25-M is variable depending on the particular workload, but the differences are not hugely significant, excluding sequential write speed.
The X25-M is however not really an enterprise class drive, even though it can provide enterprise performance. Depending on how heavy your work load is you might be better looking at something like the X25-E.