OVF is superior to EVF.
First, it is not healthy to have screen radiation this close to the eye. Or not this close, computer screens are not healthy, they just necessary evil with computing.
Second, EVF consumes battery. Not only in obvious way, but with OVF you don't even have to turn on camera to check composition.
Third, EVF is inferior in the light changing. I'm not sure in which Cannon EVF they have auto brightness like in Olympus, but it is still inferior electronics between light and human eye.
Fourth, panning with EVF sucks. You might have to pay $$$$ in the hope it won't, but even Rebel is still superior for panning.
OVF is superior in many cases, agreed, but not all.
Yes, EVF does consume battery, so there are settings and features to help reduce power usage elsewhere to compensate. So agreed there too.
EVF is not inferior in light changing, I set my brightness and it doesn't change on me. Perhaps you are thinking about the rear LCD? The EVF doesn't have to change brightness since when I press my eye to the cup, whether its light out or dark out, I have my EVF right where I want it.
Panning certainly acts a bit odd with EVF, but refresh rates get faster and faster, and eventually this won't be an issue.
None of this negates my points where EVF is superior though. 




