I was at a farm that had 3 2588's one with aST rotor,I couldn't stop wheat loss on the rotor . The other 2 were doing agreat job. This was a very hard to thresh hard spring wheat, on any other wheat the rotor works very well,I have not had any trouble in any other crops if the right concaves are used. side by side the 8010's, the one with the ST will run at 85% engine load, large tube will run at 105% engine load. If your wheat threshs easy by all means get ST rotors.