They're one of my absolute favorite shafts to play in my irons. And I'm in good company. The Aerotech SteelFiber shafts also have more PGA Tour wins than any graphite iron shafts in history, and are used by many players (including World No. 2 Nelly Korda).
And now one of you is going to win your own FULL Set of (11) Aerotech SteelFiber Private Reserve shafts. How are the Private Reserve different? I'll get to that below but in a nutshell if you were a Tour pro the SteelFiber Private Reserves are as exacting as any specifications you could ask for or want.