Compact body of Leica Q2 makes it much easier to carry it with you all day. Environmental Sealings
For a camera that you carry everywhere with you, being weather proofed is a big advantage. You will have one less thing to worry about. Large Full frame (36 x 24 mm) sensor
Large sensor in Leica Q2 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. RAW shooting capability
RAW files contains much more color information compared to JPEGs, and gives you more room for post processing without significant quality loss. They provide wider dynamic range and option to recover shadow and highlight clipping to some degree.
Carrying this weight all day may not be very comfortable for you. Body Thickness 92mm
With a thickness of 92mm,Leica Q2 is not a pocketable camera for sure.