Still living in that middle ground at 67 years old where I prefer steel iron shafts for heft and consistency, but graphite is easier on the body. I just shafted up some Wishon 752TC heads with Apollo Acculite 75 shafts, R flex, soft-stepped 1.5. Only played 9 holes, but I'm pleasantly surprised at the feel and launch. The 5 shafts (6-W), weighed right around 80g, uncut. One was 78, and one was 83, the other 3 were 80, 80, 81. I put the 78g in the 6i and the 83g in the W.
I have a nice set of PING i3+ irons with stock graphite and am thinking of trying the Nippon 8950GH in senior flex (.355). Any other lightweight steel options?