I also turned mine off. But I don't run "suspicious" things in that PC nor do I visit "strange" sites (in fact, that PC is my "Vue machine" and it's disconnected from internet). If I would use that computer in a normal way (downloading stuff, installing, uninstalling, installing again, going to all kinds of sites, etc) I wouldn't have turned UAC off.
The concept of UAC is a good one, IMO, and, like the article says, it's mainly annoying when you are still in the process of installing everything you need in a new PC (which in my case takes months... :-)). Once that is done, the warnings from UAC become less frequent.

So, in short, if your PC is a pure "Vue machine", disconnected from the internet (or almost), it's safe to turn UAC off. But if you use your PC in a "normal" way, browsing through all kinds of sites, copying and downloading stuff constantly, than you should keep UAC on, just like the article says.
Just my two cents... :-)