<p>Applying ED affects admissions chances materially. There's debate about EA, but I don't think it makes much of a difference (compared to other applicants who file mid-fall, that is; applying in February definitely hurts your odds in comparison to EA).</p>
<p>Generally, the earlier you file, the better off you are. Some don't have EA so much as "early notification," in which you are guaranteed a decison by a certain point... which is a modified EA. </p>
<p>Apply as early as possible and keep in touch with the schools.</p>