NO to automatic updates. Absolutely NOT.

A friend recently updated to WP 3.6 and it broke every single external link in his posts. Every. Single. One. Who knows why... a bad plugin most likely, but IT HAPPENED. Now I'm afraid to upgrade myself. And it's not the first time a new major WP version causes unexpected behavior.

I don't care how careful you guys are. Incidents WILL happen. You DON'T go around breaking websites left and right because "you just know" that upgrading immediately is the right thing to do for everyone. At least if I update manually and something breaks, I'll know it happened.

The road to hell is paved with good intentions. Never force things on people. Never ever.