Well, Michael Reichmann whose main camera is a Phase One P65 so is used to rather higher technical quality than about 99.99999% of photographers, disagrees.
I recognise that without testing the thing yourself, other people's opinions are just that, but I have no reason to distrust what MR says in this kind of review. He liked it enough to buy one for himself.
Here's a selection:
" it's hard to find any fault with the X100's image quality, especially when combined with its mated lens, which is similarly first rate."
"I am familiar with the amazing low light capability of the Nikon D3, and I am confident that in terms of high ISO noise performance the X100 is close to it. ISOs up to 3200 is so relatively noise free that I wouldn't hesitate to use any speed, even for critical work. 3200 is very good, and even 6400 only needs a bit of clean up (especially in B&W) to be very usable. ISO 12,400 is an available boost setting, is noisy, and has some blotchiness but will be fine for photojournalists photographing black cats in coal mines."
"In reviewing what I've written above, you'll have noted that I am overtly critical of some aspects of the X100's user interface. Indeed it is because the camera is otherwise so good, and the image quality so exceptional, that its UI flaws are all the more glaring."
"Otherwise it's hard not to be excited about the X100. For serious photographers who value high image quality in combination with eye-level non-reflex viewing, this is a camera to cherish. The excellent build quality also helps to justify the relatively high price of the X100. I doubt that anyone with the wherewithal to purchase this camera and the interest in what it has to offer, will ever regret its purchase."
A personal view, yes, but so is yours. I suggest you just wait until a wider selection of sites publish their reviews and make images available.
--
Galleries and website:
http://www.whisperingcat.co.uk/default.shtml 
