Hardcoreware.net has posted an in-depth
review of Microsoft's latest service pack, SP2. If you have been thinking about upgrading your system, this is worth a read.
Conclusion:
After looking at the results, one thing is certain: You have more to gain than you to to lose by installing SP2.
Performance is for the most part identical to SP1, except in a few cases. In those cases, SP2 was actually faster! There were only one or two instances where SP1 was faster, and that was by the slimmest of margins.
What surprized me was how much gaming performance was increased by upgrading to SP2 and DirectX 9c! I was NOT expecting this, especially on the midrange x600 XT card we used for testing. Nonetheless, most games do benefit from the upgrade.