For me it is the enjoyment of building and the craftsmanship that it takes to create a model to scale. Then the reward is being able to fly it and see it in the air. Plus competing with and against a great group of other modelers that share the same interest. I enjoy building a sport model too from time to time but they don't have pitot tubes, panel lines, antennas, rivets, etc. and there is or never was a plane that is represented in full scale. It is a labor of love that not every one will ever have or understand. My 2 cents.