The owner of the 980 I maintain had the MT's installed a couple of years ago. We lost a good 8-10kts over the Hartzell Wide cords. He mainly wanted them for the noise reduction. They are quieter than the Q tips and engine starts are cooler and quicker for sure. We gained almost all of the speed back by adjusting the engine Comps about 12 degrees. We had 28 degrees of margin available. You probably won't lose any speed if replacing the Dowtys. The owner is very happy with them.
