If the OP is any indication of the sort of writing a non-native writer would produce, then I can say that yes, a native writer will do a better job for you ninety-nine times out of a hundred.
That's not to say that non-native writers are incapable or stupid. Far from it. I'm tutoring a few international students in academic writing right now. They're very smart; they just have problems writing grammatically correct and natural-sounding English. In my experience, most non-native English speakers retain a few recognizable quirks in their writing, even after years of practice writing formal English. This is only natural, but it also means that I wouldn't hire a native German speaker to write a college-level English paper, just as I wouldn't hire a native English speaker to write a college-level German paper.