I agree that there are still good reasons for sometimes wanting a one-eyed "peep-hole" VF, like you new point of blocking out distractions, and as you can see by my question above, I am still actively wondering how much the gap has been closed by improving LCD technologies. But manual focusing is probably not such a big negative anymore. And sometimes, I greatly like being able to work "heads up", maintaining eye-contact with a subject or keeping an eye out for incoming traffic that could ruin my photo. So I do greatly like having the rear-screen ... as an option.
As to steadying a camera: I never pushed the camera against my face, and in fact I fear that head movement could actually make things worse than relying only on my more steady torso. One option that some recommend is a short strap, so that the camera is held pushed out with the strap tight, using the back as a third anchoring point. Anyway, between very usable medium to high ISO speed settings and image stabilization, I think we can now chill a bit about absolutely perfect camera holding technique in most cases.