> It's because D3D is still reasonably quick (although not as quick as OpenGL)
While I believe that OpenGL is better for everyone if only because it's an open standard, I think that one article noting a difference between the two APIs should not lead to the conclusion that "OpenGL is faster than D3D, full stop".
Your reasoning is definately correct. I haven't made enough measurements myself to justify the statement, but the couple of times I did, OpenGL was usually a tad quicker. However that's more anecdotal evidence than anything else.
While I believe that OpenGL is better for everyone if only because it's an open standard, I think that one article noting a difference between the two APIs should not lead to the conclusion that "OpenGL is faster than D3D, full stop".