I received the Q-S1 this morning. Here's 2 casual photos.
Great little camera
First impression.....
Build quality - Camera looks great! I really like it. Camera is not plasticky as I would expect. It actually feels quite solid. The knob on the right hand side is really quite well placed (to me of course). My finger can slid in between the knob and the lens and the rest of the hand use to grip the camera. I like it. It is small but compare to my wife's NX mini, I think this feels a lot better on my hand. Battery doors and SD card doors are pretty solid. No problems there. Buttons are well placed...although I prefer the preview button on the top left (like my K-3) but obviously this is not possible as there is just no space at the back for that.
Performance - I have only tried the camera very briefly in my living room which is quite dimly lit. AF speed is fast. I am quite impressed. AF accuracy is so far so good. Need more testing of course. Noise performance is acceptable considering the sensor size limitation. I think it is better than my S95 and really quite close to my wife's NX Mini. Need to do some tests.
Flash - Have not tested the onboard flash all that much but tried with my Metz 20 C-2 flash. Direct flash and bounce flash works well. No lagging of any sort that I can detect. So far so good there.