See my Leica SL wishlist at B&H Photo.
I experienced consistent problems in the field with both autofocus and focus shift. Both issues are extremely serious in that they destroy image quality.
This studio evaluation confirms my findings. I deem it alone worth the price of Guide to Leica for anyone considering the Leica SL.
Includes images from f/4 - f/8 including actual pixels.
UPDATE: I’ve added a second series from f/2.8 - f/11, this time using manual focus to ensure sharp eyes to start with. Combined with the AF example, the practical value of the operational behavior is even higher.
This study is at a reproduction ratio of 1:16.3 as determined my measuring the subject. It corresponds to a loose head and shoulders portrait, thus it is a critical operating distance. Since the 24-90mm focuses down to 1:3.8, this is a far greater distance than its closest focusing capability.