Haha. I was meaning true monochrome cameras without the color array filter ( like the bayer or x-trans ) in front of the sensor. Like Leica monochrome cameras ( Leica M9M and later models ). You get a lot more detail that way and theoretically tonal / gray separation should be better as well.

I do actually have two Sigma Foveon cameras ( DP2 and DP3 Merrill ) where the sensor is layered and each RGB pixel is layered on top of another. The detail you get out of those sensors is amazing the first time you see it. Black and white converts better too. That said I would still like a true monochrome camera to play with at some point.

Do you know of a "blind" A-B comparison between photos made with those different technologies?

It's not even clear to me how to establish a like-to-like sensor resolution.