I just finished the program and am reporting for Officer training tomorrow. I found out that I got excepted from another Soldier in my unit congratulating me. I was like "wait, how did you find out?". It comes out in a MILPER (think that's how it's spelled) message that your 1SG will look at.
As far as received you should have a SFC POC at USREC that will be tracking it. Once submitted I called and they verified. After you will get an email if anything in the packet needs to be corrected.
On the Soldier end I had no idea how competitive or who I was going against. To be honest I had a lot NOT going for me and I still got accepted so just submit anyway. I even got an extension and turned it in like 3 months late. Everything was still pending on mine (security clearance, classes, academic worksheet, acceptance letter from school) and I had an age waiver. The only going for me was my letters of recommendation and GPA (that was later destroyed during nursing school with almost straight B's...)
There is an Facebook site that is for Soldiers in the same boat, check it out and a lot of people can give there 2 cents cause they are in the same boat. Hope this helps a little, if anything else you can PM me or go to the facebook site (I'm there too) and will get you squared away. https://www.facebook.com/groups/GoAECP/