I shared this on another MT prop thread here, but I just installed a MTV-9 on my 114 (purchased through Carl)
-The weight savings helped a lot to offset the dual electronic ignition on the firewall. (Two 6 cylinder coil packs are heavy)
-So much smoother than the 3 blade Hartzell that was removed. (I'm still convinced something is wrong with it...sending it out soon for evaluation)
-Dynamic balanced to 0.02 IPS. I've had this thing 7+ years, and it's never been this smooth. Static wicks are rock steady, no more glare shield vibration. The avionics and whole airframe are thankful.
-With the reduced weight of the spinning mass, the engine cranks over about twice as fast as it used to.
-Haven't pulled out the official yard stick, but take off roll is noticeably shorter. Climb rate is better by a noticeable amount.
-Cruise is same or better. Maybe 2-3 kts faster.
Not sure if the MT is that much better, or if there was something truly wrong with my Hartzell (TBD). I know a lot of people have had good luck with the Hartzell. But first impression with the MT is very positive. The smoothness was my #1 hope. The improved take-off performance is just an added bonus.