The oft given benefit of mirrorless cameras like my Fuji X-T1 is the size and weight of the camera. It delivers great performance and image quality while being much smaller and lighter, so you are more likely to carry it around and no neck pain.
Additionally, with a smaller camera the entire system and support accessories can be smaller. I recently downgraded in size my tripod ballhead. I was using a heavy-duty Manfrotto 3055 ballhead for my large DSLR. I switched it out for the Really Right Stuff BH-30 compact ballhead.
The Manfrotto head is 28.8oz and the new ballhead is 60% lighter at 11.2oz, you can also see in these photos a significant size difference. The biggest plus for me is that I can now leave the head on the legs and it all fits in my tripod bag.
Really Right Stuff is high quality and amazing, but not cheap. I expect it to last me 10+ years so worth buying for quality. They also make a Fuji X-T1 plate which I now just leave on the camera, barely noticeable and makes it super easy to get on and off the tripod.