Large APS-C (20.7 x 13.8 mm) sensor Large sensor in Sigma SD9 ensures a good low light image quality compared to smaller sensor, and it also provide shallow depth of field and a nice blurry background when needed.
Large Body Even the smallest lens attached to this body will be a burden to carry everywhere with you.
950g Carrying this weight all day may not be very comfortable for you.
Body Thickness 79mm With a thickness of 79mm,Sigma SD9 is not a pocketable camera for sure.