I have a Magnum .52 and the carb that came on it was jacked up right out of the box, the barrel stop didn't work, it just let the barrel slide right out of the body. The customer service guy at Magnum told me to send it in and so I did, low and behold almost 3 weeks later he is claiming that I didn't send it in and that it "must have gotten lost in the mail". Baloney I tell him, I sent it and I have proof of postage to prove it. I called in several times and the last time I called he hung up on me. Well, the next morning the carb magically must have shown up because the guy calls me in the morning and tells me he "found the package" and is sending me a new carb out. Overall frustrating experience and felt like I was being called a liar every time I talked to the guy.

Magnum seems low end to me, the materials and the workmanship seem sub-par. (my only experience is with the 2-storkes) O.S. on the other hand has been ROCK SOLID! I have an OS .46 AX in my Extra 300, and OS 61 FX in my Su-Do-Khoi profile 3-D plane, and an OS .46FXI in Nexstar. All of them are fantastic motors.  I also have a Thunder Tiger GP .61 that I have had great luck with, so I'm no OS only fan boy type.