Your Xbench score is extremely low, this drive is capable of about 700MB/s R/W. Try another benchmark like Blackmagic (free) or Quickbench (paid).
Anyway thanks for sharing this. How much is it, if you don't mind asking? Seems that ATM it's only available in HK.
Edit: I see why the benchmark numbers are low: you've put the card in slot 3 which in 3,1 is PCIe 1.0 x4. Card has x4 connector but its Marvell controller is only x2. So in slots 3 and 4 you can achieve ~400MB/s max (due to 8b/10b encoding). Put the card in slot 2 to run the drive at full speed.
That's better
Another question: I saw MPX-3132 in your Airport slot (but no SATA cables connected to it). Do you use it? What speed does it deliver if so? I know that it's SATA II but I'm curious about real world transfers, especially with SSDs. If it would saturate SATA II bus, it would be nice.
I installed the 128g version of the card on my 2009 mac pro, but the benchmark is somehow different.