They really are something special aren't they! I've been using a Panasonic G100 and 100-300 and it's not a patch on the sharpest I remember of the RX10. Of course, sometimes you do get some super sharp ones, but its not with regularity. I can be taking a shot of something half a mile away and its just blurry, whereas on the RX10, so long as it wasn't camera shake you had superb quality. From what I remember, the high ISO quality was still pretty good with the RX10. I always ended up shooting RAW and I found the dynamic range to be pretty amazing when you pull out the shadows and drop the highlights!