Significance of Receipt Date if Priority Date is the same

[ushkand]

Here is my situation:

I made two AOS applications based on the same I-140 during July and both have been receipted so far. I am looking for advise on which application to keep.

1st Application Details
Reached NSC on July 2nd - received both RN and FP notice from TSC.
No medical exam
DID NOT APPLY FOR EAD.

Total Check amount (incl Spouse) Cleared - $790.00

2nd Application Details
Reached NSC on July 19thd - checks cleared on 09/12/2007.
Application is complete with Medical Exam
Applied for EAD for both spouse and I.

Total Check amount (incl Spouse) Cleared - $1,150.00

So here is the question - I have already lost fees on the applications ( I have reconciled with that and not having to pay an attorney $2500 for filing 485 made it less painful ).

I am planning on requesting USCIS to keep the 2nd app and return the first one so that I don't have to apply for EAD with the new fees.

Since the first application has a RD of 07/02/2007 and the second one an RD of 07/19/2007, is it worth for me to keep the earlier RD and spend additional $680 on EADs on top of the $1150 I already lost on the second app?

TIA