I've always been an ardent user of open sights, however, age and failing eyesight led me to try other sighting systems. I tried scopes (again) for a short while, but found that they still weren't quick enough for me as a still hunter, and they also seemed to be a magnet for snow, leaves and evergreen needles rendering them useless.
I first experimented with red dot sights about 10 years ago, and quickly became a devotee. Now more than half the members of my hunting camp use them as well. All of my hunting rifles now wear red dots, and I've put a holosight on my favourite deer rifle (my BLR in .358 Winchester).