I just started putting mine together today. I must say that World Models has a very nice ARF. The hardware is nice and I like the extra touches like the dummy cowling and the upgraded tail landing gear. This is the first plane I have built where they even provide the foam to wrap your receiver/battery in. I have a Saito 72 and an 82 that I can use. The 72 is in my Twist right now and has plenty of power for that plane. The Ultimate is supposed to weigh in at 4.5 pounds, I'm wondering if I will need the 82 in this plane. I have a 40 size P-47 in the works and the other motor is going in that. I want to make sure I have plenty of power in the Ultimate for some 3D stuff because the warbird is going to fly in circles all day long. Isn't it fun to be the first people to own a brand new plane, we get to do all the homework for the people who buy them later.