Both Leica Q3 43 and Leica M11 have Full frame sized 60.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Another difference between these two cameras is that Leica Q3 43's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the Q3 43 and M11 sensor size comparison.
Sensor Size and Resolution Comparison image of Leica Q3 43 and Leica M11 Cameras
Leica Q3 43 and Leica M11 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Leica Q3 43 has 29% larger pixel area compared to Leica M11, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Leica Q3 43
or the
Leica M11 ,
including hyperfocal distance.
