Although I'm late to the party in reviewing Windows Vista SP1, it's becoming widely available as I write this, so now is as good a time as any for my review. Rather than try to cover every improvement in SP1, I'm going to cover my particular experiences. Read my review.
Blogger Jeremy Toeman had problems with his Sony Vaio Vista laptop that were so bad that he actually gave up and bought a MacBook. Ed Bott read about the problems and fixed them. In short, Ed did a clean Vista install, tracked down missing drivers and disabled some startup items that were causing problems. In the end, the system was actually stable and fast, which was an enormous change from the way it was shipped from the factory.
The lesson here is not that Vista can be fixed. The lesson is that Microsoft would be insane to continue allowing PC makers to install crap software, cruddy utilities and junk security suites on Windows PCs. Vista is a fine operating system, but my experience with it has only been on clean installs. Most people get Vista in the state that this Sony was in, where the manufacturer loads so much junk on the PC that Vista does in fact appear to suck. This is why Walt Mossberg panned his Vaio, which lead to a lot of other "Vista sucks" posts in the blogosphere. Microsoft continues to allow this practice at their own peril.