We have learned that CL9 works fine, because we can run the chipset with low latencies. If we reverse the settings to CL7 and increase the chipset latencies, we got worse scores and the board gets unstable. The FSB is also important here. The Corsair kit even runs at 1600MHz with 400MHz FSB, but only yield bandwiths similar to 333FSB with only 1333MHz memory clock.
The results for such expensive memory kits are just poor. DDR3 PC3-1067 can give you a one per cent gain compared to DDR2 PC2-800. 1333MHz gives you another 1.2 per cent gain, with 1500MHz adding a further one percent. DDR3 1500MHz is roughly three per cent faster compared to DDR2 800MHz, but now you have to pay four to five times the price for DDR3 to get there. This gain will only show in memory intensive programs, such is the first pass of XviD encoding, as the second pass revealed that 0.8 per cent is the maximum gain.
DDR3 is far too expensive to justify the upgrade. When you are planning a new computer, DDR2 is just fine and you can save around $300-400. Use it to buy a faster CPU or a faster graphic card.