I've had an X1 for a few months. I use it as a backup for my M9 when I am traveling -- and for when I want to go really light. All of the minuses described above are true -- especially the autofocus, which is slow, and the clumsy autofocus/exposure lock. I wouldn't think of using it for fast moving subjects (like little grandchildren) as the autofocus and shutter lag conspire against work like this. I would rather use my M9 prefocused, or a DSLR for that.
The plus is that the quality is superb, DSLR quality in a very small package.
I would definitely not be happy with it as my main camera but for the uses I make of it the pluses outweigh the minuses. I have a finder and I use it especially in bright sun where the screen is hard to see (I got a used Voigtlander 35mm finder, which is fine; I am not one who insists on Leica or Zeiss quality in a viewfinder as opposed to lenses).
By the way, I went from a Canon G10 to the X1. The Canon shares some of the detriments, has a viewfinder that is barely adequate, and produces files not as good. I gave it to one of my sons.
Bottom line is I am still searching for the perfect small sensor camera and haven't found it yet.
The M9 will be kept for a long time I suspect. The X1 until something better (X2?) comes along.