Is that 'still' the question after this?
Computerworld is reporting that Windows XP Service Pack 3 runs MS Office 10% faster than XP SP2 — and is
'considerably faster' than Vista SP1. XP SP3 isn't scheduled to be released until next year, but testers at Devil Mountain Software — the same company which found Vista SP 1 to be hardly any faster than the debut version of Vista — were able to run some benchmarking tests on a release candidate of XP SP3, says the report. While this may be great news for XP owners, it is a problem for Microsoft, which is having trouble convincing business users to migrate to Vista.
Windows XP SP3 boasts speed boost. Leaves Vista in the dust.