i was not going to get involved because I personally dont like the Plane but just a fact , Magnum engines are desinged and enginered by a key enginer that was with OS . So the quality and thought process is the same or better , I have personally purchased the OS based on every OS snob telling me that it was the only engine in existence . Then when visiting Southen Cal i stopped in a Hobby Shack now hobby People and talked to an old timer RC pilot .He gave me the facts and I tried one and have never gone back . For the record I can afford much better the Os so its not a cost issues , its a feature and benifits issue VS marketing and advertising issues . I was fooled the same way with Robart gear , went with the GURUs suggestions on Robart , now for 120 size planes and under I only but century . Ya I know there are a ton of post on both companies, again just put them side by side compare the cost and do a benifits/features analysis and see the one that wins .