Manual update for me for Windows. I turned on my laptop the other day, for the first time in quite a while and I got a message saying it was installing over 29,000 updates 🙂
I just use the Default Automatic updates, so I don't forget to update it, and Automatic updates has been working pretty good for me, and never failed or wreck my computer in Windows 7.
Automatic updates also don't really slow down my computer since I usually just use my computer for basic tasks like Web browsing, e-mail, office tasks, and listening to music.
I run auto updates for all my machines unless it is being used as a live server such as a web server then I turn auto updates off because obviously i can't have it shut down randomly because this will cause my website to crash.
I think there is a section in Windows update to uninstall any update by picking the update you want to uninstall, but it is usually not recommended to uninstall updates since updates are used to make your computer safer, and perform faster.