Clark's Grebe?

When I saw the Grebe above, I assumed a Western Grebe as it seems most I see are. Looking at these pictures again tonight, I've swayed myself into thinking that it is a Clark's Grebe. It's harder to tell them apart in the winter as the Western Grebe gets a little smudgy around the eye and the Clark's Grebe darkens above and to the sides of the eye, but I'm going mostly on field guide information than on experience.
Bill color is also an indicator, but isn't much help in this case, in my opinion, as the bill looks bright yellow in the sun and dark when it is shaded.
What's swayed me is the fact that the eye is only half covered with black, with some smudginess of the black around the eye. I may be wrong, I have been before, but that's my conclusion. As always, comments welcomed.