Jacked69, You hit the nail on the head with the camel, with those type wings at low speeds it will tend to rotate left to right because there is not enough air traveling over the wings laterally so landings are a bit tough as you saw in the video, a good friend of mine said that it the plans looks hard to fly by a experienced flyer then its probally VERY hard to fly. The best thing about the cherokee is that it has flaps, its the flaps that make landings so smooth and slow, its great. What did was i took out all the parts from my trainer (.46 engine, 4 servos,on/off switch,Recivier) and put it all in my cherokee and it flys great. Now I will say that it is somewhat easier to build than most ARFs but it will propally take 5-7hours and it will be done, the build is straight foward..it was actually the first airplane ive ever built and i had zero problems with it. As for your P-51 if you want to go with a larger engine then go for it, remember you can always throttle back if its too much but just be aware of weight and center or gravity =)