It is pretty hard to beat the Mauers. 300+ bu is probably only going to be accomplished with the upright extensions added to the standard. With the base extension, you are probably looking at about 275bu in corn. It is a good place to start. You can always add the extra ones. As far as damage, use common sense. With some little precaution and common sense, like not being loaded through ditches, big side hills, etc., you should have little trouble. And also, it never hurts to check regularly axles, frames, and anywhere a load can stress the machine. Most breaks start from small cracks that can be caught ahead of time with some watching