Have 9 Gordon Rotor Bars in the front of the rotor and the back half is spiked rasp. Works awesome! Never tried it in corn but for soys, dry beans, wheat, etc. they work great, they are well worth the money. We have many updates on our 1660 and it has been well tuned to all of the crops that we raise. We do have cover plates for the front 1 1_2 concaves when necessary. So to answer your question, yes they thresh better, gentler, and run smoother, last longer, and we haven't had any problems with them whatsoever *knock on wood* and even though expensive, over time they well pay for themselves. This is my opinion so take it for what it's worth! Ed