Early Decision is for those students who are very committed to applying to one particular college.
If you are going for Early Decision means the applications have to be due in the college office by October 17th in order to meet the November 1 deadline. Early Decision is only for students who are 100% certain they will attend that particular college.
Early Decision is more competitive and you must meet all the requirements for admission. If you still need to improve your academic record with senior grades then you should rethink about doing early decision.