If I have contacted the seller within the prescribed time. If I have paid for my transaction within an acceptable period, and if the seller has received my payment I have done EVERYTHING I am required to do under the terms of the buyers agreement as outlined by ebay.

If the seller has received my payment, my end of the transaction is complete.
Unless the seller is running a scam, mis represents the item or never ships it he/she has no reason to believe that I would post anything but positive feedback for them.

The idea of waiting is obvious, If I receive the item and it is not as described, damaged or whatever and I leave a negative for the seller this affords them the avenue to get even WITHOUT any basis for doing so.