About five weeks ago I said, "Its closest competitor is the Fuji X100s, which is a pretty highly regarded camera, and probably a better camera than the GR. The Fuji camera costs significantly more, so it will be interesting to see if the price difference is equal to the quality difference."
DxOMark has recently tested the Ricoh GR, and now we can see how it and the Fuji X100 compare. DxOMark tested the sensors and not the lenses, and while both cameras have excellent lenses, the Fuji lens is generally considered the sharper one. The GR doesn't have an anti-aliasing filter.
The Ricoh GR, to my surprise, actually outperforms the Fuji X100, according to DxOMark. The GR has better dynamic range and color depth, while the X100 has better high-ISO performance. The differences aren't huge, but considering that the GR is less expensive, there are really compelling reasons to choose it over the Fuji camera.
Now DxOMark hasn't tested the Fuji X100s, which is an improved version of the X100. It will be interesting to see how it compares.
For those considering purchasing the Fuji X100, you may want to take a close look at the Ricoh GR. For about $250-$350 less (depending on where you shop), you can get essentially the same thing. More so, the GR might actually be the better of the two cameras.
This post has been updated for corrections.