Sorry to dig up an old thread but seeing as how I was the one that wrote the phoblographer review I'd be happy to answer any questions.
Additionally it's ironic I should be finding this post as I too have the X-Pro 1 with the 14mm (a great lens in its own right) but I just rather shockingly discovered that the GR + GW-3 is sharper wide open than the Fuji, and they match up around f/5.6.
The GR + GW-3 has a slight bit of CA through the highlights (easily correctable) and if there is a strong backlight you might see some ghosting (the Fuji does not have either of these problems). Both options are pretty well corrected for distortion with the Ricoh showing only slightly more (to my eyes). I do notice a slight smearing on the far corners with the Ricoh, but there is still detail there.
Again, the Ricoh is noticeably sharper across the entire frame wide open in comparison to the Fuji 14mm.
I too am now wrestling with the idea of selling off the Fuji 14mm. I'm not terribly opposed to the idea of using the Ricoh as my mobile ultra-wide. I've done some large prints with the combo and have been very very pleased (particularly with my photos from Europe, some of which you will see in my review).
Anyways, sorry to dig up the thread but I figured I'd chime in.