Topic on Engine talk:Source
A note on D3D9Ex is that RTSS and SK reports differently. RTSS only concerns itself with swapchain data if I remember it right, so it only reports a game as using D3D9Ex if it uses FlipEx (the new swap effect introduced in D3D9Ex). However SK reports games making use of other D3D9Ex related calls (once that RTSS doesn't hook/care about) as using D3D9Ex even if the swap effect might not be FlipEx.
This means that D3D9Ex testing is at the moment flawed unless aware of these details and how reality might be different from what's being reported.