1515 1y chinese cc neu motor vrs real american made neu motor

[Rivermaxx]

This has probably been touched on but is there a difference in power output between the 2. I know there is some diferences on how they are built but is one motor considerably better made or better materials than the other or last longer or possibly more efficient. I am getting one or the other for my silverback build but not sure which one yet. If I get a new traxxas one off ebay I wonder if it would still be under warranty.