I applied early decision for last year and am thrilled that I did but do not do it unless you feel that this is definately the school for you. It doesn't hurt you in anyway to apply early other than the acceptance deposit may be slightly higher and if you do get rejected, no you don't get put back into their regular interviews.
It isn't about having the best numbers but whether they feel that your application indicates that you will be a really good fit for their school. My EC's and life experience made up for most of my defaults in scores and gpa and I was lucky enough to get accepted thru EDP.
Interviewing in EDP or in the fall, your application is weighted the same, the only difference is that in the EDP there are still more spaces left open to fill than there will be come October or November. As a result, a so-so applicant will have a better chance of getting in the earlier they interview.
Good luck and again, only apply EDP if you really think this school is a good fit for you. Once you are offered an acceptance, you must withdraw your application from all other schools.