All of my Savage lever guns (mostly pre-1920's) sport irons in the deer woods. They work now as well as they did 100 years ago. My 66 year old eyeballs need a little help seeing those front sights, but 'tain't nothin' a few tricks of the trade won't cure. I have a couple bolt guns (pre-war, mostly) that sport Lyman 48 receiver sights that get used with a fair degree of frequency too (but sometimes I cheat and take along their scopes which fit into Griffin&Howe QD side mounts as backup). The rifles that wear scopes permanently are mostly benchrest queens.
Lose a few minutes at dawn/dusk? Meh, who cares?