D 600 Live View
That's strange not to have it because even my four or five year old Sony P&S has this feature. The technology exist, I guess they just didn't want to add it to the price of the camera.
Sony has a poor implementation, though - when you activate exposure comp, the histogram goes away (when you need to see it) then returns after you deactivate. At least that's how it's been on all the Sony cameras I've owned, including current cameras like the RX100 and A57.
Surprising to hear about this omission on the D600. Even the T4i has a live view histogram, and RGB to boot. Makes ETTR very easy, as well as avoiding blowing the red channel.