Having bought a used X100 a little while ago, I decided to give my GR a rest while I tried out the former. My first impressions are as under:

 - Image Quality: Given that this is an old EXR sensor (12MP, with the AA filter) this lens is incredibly sharp.

 - AF: Not the fastest horse in the race but good enough for most people's needs.

 - VF: Exceptional ... coming from the GR series, you never knew what you missed till you try this dual VF.

 - Handling: Still getting used to it. Not quite the Ricoh. But then ... there's an intuitive set of controls (harking back to DIY, everything manual) that are something of a pleasure to use once you begin to relearn what to do with this camera in your hands.

 - Colour: Absolutely stunning. This camera will make you (as does the GR) want to shoot with colour again.

 - Overall: Un-pocketable compact with SLR style handling and great IQ.