The final resul t should be polished and visually pleasing. Writing a personal statement should be approached in the same way as you would approach a serious essay. This means that you should do a number of drafts. Give it to a friend to see if it conveys the right images. In general you should not use exactly the same personal statement for each school.
Different schools have different objectives in admitting their first year classes.
In the same way that you would not send the same resume to different employers, you should not send exactly the same personal statement to each school. Here are some general guidlines for how to construct personal statements. The personal statement is about you. Make it personal. Write about you.