Another vista service pack 1 question?

You are fine. Saving it will allow you to transfer it to a media device and save others the time of downloading it.

I installed SP1 on my Home Premium 64bit Vista yestersay, and things are running normal. Haven't noticed a change, good or bad.

I would hold off a week or so on Vista SP1. I don't know how wide spread this is, but I have seen problems posted on several forums related to SP1 causing new problems. Apparently some people are experiencing Blue Screens of Death (BSOD) and incomplete or failed installations due to unapproved drivers. I'd wait a week or so just to see how the situation works out.

As to saving or running, personally I tend to save the file, virus scan, then execute it, especially for larger files. I'll also opt for offline installers (bigger file size, but it is the complete installation) rather than the smaller web installer that often is available (this one is a smaller local app that checks to see what you need and only downloads patches that apply to your specific computer/installation). Given I tend to install it on several systems, it is easier on my network and a bit less time consuming.