Microsoft released SP1 for Windows Vista this past week and the reviews seem to be mixed. Some reviewers say SP1 improves various system performance tests, and others say it does the opposite. I installed Vista SP1 on my main desktop PC last week, and the installation process was flawless. As far as any "real world" performance issues, I haven't noticed anything either way. On my system, I have had no noticeable performance gains or slowdowns as others have reported.
I haven't installed SP1 as of yet on my HP laptop, as the SP1 betas I have used kept constantly BSOD'ing my machine. I was never able to narrow down the culprit, but I am a bit wary about installing it again on this computer. I might fire up Windows Update tomorrow morning and give it another go, so we will see how that works out then.
Otherwise, my question to the community is have you, Vista users, updated to SP1 yet?