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 APS-C (23.6 x 15.6 mm) sensor
Large sensor in Fujifilm X-T1 IR 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.
Medium size Body
With relatively smaller body compared to DSLRs and better ergonomics compared to Compacts,Fujifilm X-T1 IRis a good compromise between size and functionality.
Carrying this weight all day may not be very comfortable for you. Body Thickness 47mm
With a thickness of 47mm,Fujifilm X-T1 IR is not a pocketable camera for sure.