If you are looking for a comparison between the X100 and a m43 setup like the OM-D, I can offer one.
The OM-D, particularly with new lenses, offers much faster and more responsive camera than the X100. AF is super fast and accurate, with almost no racking of the lens for focus in difficult conditions. Burst mode is much faster, shot to shot time is almost like a pro level DSLR, and the entire shooting experience is one of ease.
Today I was shooting with the X100 for Chinese New Year, along with the OM-D. I really noticed the difference in AF speed; where the OM-D seemed like it locked on instantly, I could feel the X100's AF motor whirring in my hand. It was quite noticeable. There was an unfortunate difference in shutter lag as well.
On the other hand, the X100 delivers an entirely different colour profile and look when compared with the OM-D. In many ways I prefer the way Fuji does colour, particularly the X100. There is an emphasis on blues, greens and yellows that I really like, and skin tones with the X100 are very nice indeed. The OM-D, when shot in raw and processed with Lightroom, tends towards a much warmer, redder tone. Skin ends up looking more brown or yellow rather the the usual Fuji creaminess Interestingly, even the X10, with its 2/3" EXR sensor, delivers a more accurate and pleasing (to me) colour profile than the OM-D.
Also, the X100 has files that just seem to have more 'depth', and this is not a comment about shallow depth of field. I think that the aps-c sensor of the X100 is able to show more subtle gradations of colour than the OM-D, which adds a sense of richness and depth that the OM-D doesn't have, IMO.
Being used to the speed of the OM-D, I found the X100 a touch annoying in the AF speed and shutter lag. On the other hand, whenever I pressed the shutter button of the X100, I knew that I had just produced another image with those lovely Fuji colours, so the trade off was just about even. In less demanding conditions, like simple snapshots or slightly more deliberate shooting, this would not be an issue for an X100 user.