I have had very good experiences of X-Pro1 as a B&W camera. There are two main reasons for that. First one is that X-Pro1 has very nice in-camera B&W conversions. Usually I love to adjust highlights and shadows to +1 to get more contrasty image. Second one (and this is the big one) is that I am able to see in monochrome using the EVF (and with LCD too of course). Because composition and textures are very important elements in B&W photography this feature really rocks. It is like a new world. Helps a lot a hobbyist like me who have been mainly shooting color photos.
I usually combine in-camera B&W with VSCO Film B&W presets in Lightroom post-processing. Those are fantastic presets with very nice film-like grain.
It may well be that my X-Pro1 will became poor man’s Monochrom.
Here are few examples of X-Pro1 in-camera B&W combined with VSCO presets: