The Modus3 120 stiff are the only steel shaft I have liked in the last decade, so maybe my experience will help.
I agree with mrtkopa, weight is the biggest change. I’ve tried the Steelfiber i80s and Recoils at 70gm and 80gm, and failed miserably with both. Hated the feel of the Steelfibers. Recoils felt nice, but I really thought the light weight made it hard to get my timing right. The lighter weight only resulted in about a 1/2 club increase in distance for me.
I’ve only hit the Catalyst in the PGA store – it felt nice. But I still think the weight would get me.
With the cost of the modern graphite, I’d suggest you just build a tester 8 iron and see how it works for you.
i’ve thought about swingweight and timing, but was more interested in shaft-to-shaft comparisons (graphite to steel flight/torque/feel characteristics), and how one of the graphite guys might be a better build than the others from a quality perspective.
i have hit the recoil 460 zt9 (f3) a handful of times and it felt ok, but i just might have to go the 8i test route. thank you –