As racer and I have talked about at length through PM's, I don't like this.
Simply because I don't like to edit my original post after something has sold until I get feedback on it. That way, if someone buys and gets something from me, and they think something is different about it than what the post said, they can then go back and look at the original post that HASN'T been edited since before they paid, and know that they got exactly what they paid for. Therefore ending any speculation that they got ripped off.
Sometimes I will edit the first post after the original to say sold before I get feedback, but not the original.
Just my 2 cents.....