You're forgetting the biggest problem with Windows Update - it automagically checks your system for holes, downloads a self-extracting .exe patch to a temp folder, runs it, and deletes it.
This is fine if you never have to reinstall Windows (which I seem to do every few months). MS used to have a "corporate downloads" page with all the patches as plain .exes to download manually (for sysadmins to download the patch once and install it on all their computers), so I used WinUpdate to check what I needed, then went to the corporate page to actually get them. That way I could put them on a CD with my backups and have a reasonably up-to-date Windows install just from the Windows CD and my backup CD, without needing to re-download everything. Unfortunately, a few months after I discovered it, MS stopped updating the corporate page. :-(
