Lloyd is a friend, but I'm gonna say this anyway -- if you're going to "test" a modified camera, then post identical example images from the same model camera not converted so we can compare them directly. It's the only way for me to know if the cost of conversion is worth it.
I suspect we'll see a net gain in accutance that is equivalent to roughly 20% more pixels over a Bayer D800E. But then we loose the ability to do creative color filtration after-the-fact in post, and must make any filtering decisions at the time of capture. This latter is really the deal breaker for me on a monochrome camera for landscape work, since often minor tweaks to color response can have a large effect on the mood of the image. But for applications where desired filtration is going to be relatively well established for the subject matter from the outset, like Street, Portraiture or Studio, I can see there might be some benefit.