I carried a SLR (Ricoh) on 10mi+ dayhikes for over 20years. I will tell you that it is all in the rigging (the bag you choose)There must bee about 15 "reject" bags around the house as I speak, because I still own a SLR (Nikon)
You have to test out several bags IN THE STORE and practice accessing your gear. The bag I liked the best was actually cone shaped, so that the camera rested inside, ready to pull out at any time. Personally, I did not like any of the chest bags (they were too big and bulky for me) Rather, I had that cone-shaped bag that could be cross strung, or worn like a handbag.
It is all about what you are comfortable with + do not try to carry too much gear (changing lenses in the field is very risky)
