Hey Duke, did you mean Aerotech Steelfiber? Which model? I'll be using Steelfiber in either the 358 or possibly the 2011. I've had the 2013 with Steelfiber and they were the best irons I've owned thus far. I love the look of the 358, just wondering if it's too small a head, meaning slightly more unforgiving. I need all the help I can get :(