And the back-to-back comparison, Epson R-D1s at left, Fujifilm X100 in the centre and Canon S90 at right.  Granted, the R-D1 has the lens hood on which is making that look bigger, but still - the X100 is quite small by comparison. 
And, incidentally…

And the back-to-back comparison, Epson R-D1s at left, Fujifilm X100 in the centre and Canon S90 at right.  Granted, the R-D1 has the lens hood on which is making that look bigger, but still - the X100 is quite small by comparison. 

And, incidentally, quite a bit lighter as well.  It still has heft, and feels good in your hand, but it’s not as brick-like as the R-D1…