I just tested my RAID 0 and compare with other people's result online. It seems not far from mean although it is not necessarily in the top tier group.
RAID 0 2 x WD1500HLFS WD VelociRaptor150 GB, SATA 3 Gb/s, 16 MB Cache, 10,000 RPM
Controller: Marvell on Gigabyte GA-X58A-UD7
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CrystalDiskMark 3.0 x64 (C) 2007-2010 hiyohiyo
                           Crystal Dew World : 
http://crystalmark.info/-----------------------------------------------------------------------
* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]
           Sequential Read :   217.007 MB/s
          Sequential Write :   229.515 MB/s
         Random Read 512KB :    60.115 MB/s
        Random Write 512KB :    99.928 MB/s
    Random Read 4KB (QD=1) :     0.842 MB/s [   205.5 IOPS]
   Random Write 4KB (QD=1) :     2.946 MB/s [   719.2 IOPS]
   Random Read 4KB (QD=32) :     3.897 MB/s [   951.4 IOPS]
  Random Write 4KB (QD=32) :     4.305 MB/s [  1051.0 IOPS]
  Test : 500 MB [C: 9.9% (27.5/278.9 GB)] (x5)
  Date : 2010/04/04 0:36:35
    OS : Windows 7  [6.1 Build 7600] (x64)