Mark,

For sure, your mileage is going to change. First, your plane with soft mount is going to last longer. I know it is difficult to prove this one. Now, I have one easy one for you to prove. I did it more than 10 years ago. Take the same plane with same equipment and servos. Make sure that the battery is full charged. Fly the SAME sequence two or three times without soft mounting the engine. Charge the battery and measure the mah/flight that you put to fully charge the battery. Now, install a soft mount in this plane. Fly again and try to do exactly the same sequences you did before starting with fully charged battery. Get the new data mah/flight. You will surprise how much less mah you will use when the plane is equipped with soft mount. I did it and the reduction was over 20%. With digital servos could be a lot more.

Other good points, the noise reduction were anywhere between 5-10 db with soft mounted engine. I have been able to measure this in several occasions. In addition, you can use smaller capacity batteries and save some weight. Well, I agree 100% YMMV.....

Good luck in your new plane.

Vicente "Vince" Bortone