Ironman, through their parent company Keys Fitness, has seriously jumped on the center drive band wagon. Unfortunately for Ironman and Keys, we have not. Looking at the core drive concept it seems that you are getting two drive systems for the price of one. You are also getting double the possible trouble for the same money. Center drives are complex in comparison to standard front or rear drive machines. If you like the center drive feel we would only recommend the True TSX or True TSXa, otherwise we would wait a couple of years to see how the durability factors shake out.