Well, it was on by default on Kevin and Anita's boxes (I specifically asked, and Kevin is very knowledgeable about such things and quite precise with regard to his PC configurations since he's our main second tier support tech), so I don't know why everyone else is getting different results than he.

Also, the earlier-linked Gibson Research article talks about it being on by default. So at least somewhere on the planet, there are people who have it on by default.