The ABW driver is a "black box" so you don't need to worry about a icc proflile. You can fine tune the image in the ABW settings box but you really don't get that much info here and you can't see your image, one the image of the woman. You still need to pick a media type. By picking printer manages color, you are letting the ABW mode make the decisions and produce the print. I still send my images to the ABW in sRGB not greyscale as I read that was the correct way to use it as long as you are not attempting to use a custom profile.
I believe there are still ways to pick a icc profile that you create for B&W on the windows side. I have not tried this instead just use the ABW mode. Like you pointed out, the images look very good.
In the Luminous Landscape LR4 video series there is a good section on the ABW mode.
Paul Caldwell
