Something also to think about is if you submit early, you will likely be competing against the people with super high stats (3.9, 35+ mcat) for interview spots.
You may also feel that getting your app in super duper early (on first day) will land you an interview spot earlier in the year. While that may be the case, I know a couple schools where they give you an interview based on your stats. Lower stat people get to interview later in the cycle, even though they submitted day 1. Some schools also wait for the "pool" of applicants to build up before they decide who gets interview spots. In those cases, submitting early or a little later has nothing to do with when you submit.
Bottomline, don't freak out so much. Submitting on first day vs. submitted 5 days later has no effect on your application in the long run. Just because you submit early on first day doesn't make your 3.6/28 any more attractive or unattractive than before.