Last week we announced that RC1 of Vista Service Pack 1 was now available broadly to MSDN and Technet subscribers.
I decided to give it a whirl as my main notebook has been feeling rather sickly of late (To be fair it is loaded with beta and alpha Microsoft software).
The good news - SP1 installed without issue and in less than an hour (although with more boots than I would like - but we plan to address for RTM). My machine is definitely more stable and various operations are now much more responsive.
The bad news - it still isn't a 100% stable machine.
But - I am happy overall as it is a step in the right direction and I suspect my machine would be very stable if I rebuilt it from scratch with SP1 and resisted putting on so much beta software :)