It's the reason I don't bother with updates. I have a router, firewall, and have protection at the port level. 0 issues since 2000 (when we got our first computer).
Rebooting for updates suck. When you put it all together, that's a lot of rebooting. Random software updates, windows updates, firewall updates, antivirus updates... I disable all that stuff, except for AV updates. Avira has been good though. AVG was brutal, you had to reboot after every single update. Not sure if it's still like that.
But the worse thing with windows update is they can sneak anything they want in your PC, that's the main reason I don't have mine on. Call me paranoid, but I don't like the idea of some big corporation having the ability to install anything on my PC without me knowing. Look when they pulled off the WGA crap. millions of machines were then "infected" with this and put offline.