The sensor in the M8 is larger than the one in the X1, the M8 has a 1.3x crop factor compared with the 1.5x of the X1.The M8 (and any lenses) are significantly heavier than the X1 if that matters to you. And as BB says you have to manually focus which I too can no longer do easily. If it were an used M9 and weight and focus weren't an issue, it would be a no brainer because of the full frame sensor. But, the M8 has the same size sensor as the X1 so it's not an easy choice. I went the X1 route and I love it but it has its limitations.
That's ok most people who own the X1 say the same thing... and become overly defensive. There are several reviews online that start by saying "A german made Point and Shoot". Its not meant to be derogatory to the wonderful camera in any way. It is in no way in relation to the term "snapshot" (even though I see no problem with that either).First of all, I completely disagree with usayit's saying the X1 is a point and shoot unless we call all sorts of other cameras the same. :