Just as an afterthought....
I also made a decision the other day...
The worst thing a man can ever do is open the console and type "fps START SHOW"
The game seems an awful lot smoother when you don't have a bright yellow display yelling at you about every slight dip in performance.
It's a psychological thing. I do wonder how many of my other "velvety smooth" games have the odd dip but I don't even notice them at the time because I'm not staring obsessively at the fps constantly.