I haven't seen this documented anywhere, but the pagefile seems more stable with SP3.
Pre-SP3 my pagefile always had scores or even hundreds of fragments. Occassionally this fragmentation would cause a fault in the pagefile addressing and result in a BSOD. Just as occassionally I would defrag this file with the System File Defragger and life would go on until next time.
Ever since installing SP3 the pagefile has not gone above 1 fragment. Maybe it's coincidence or righteous karma.
Note: The first boot after installing SP3 resulted in, wait for it, a BSOD from a page fault.