Sounds like more than just a 'sidegrade' when you envision another 5-10% atop the advantages the 5800K already has over the 9550;
http://www.anandtech.com/bench/Product/675?vs=50
He's getting what...20% over the stock Q9550 with richland?
Not worth the money. If you are going to upgrade then upgrade to an i5 or 6300 (why buy richland with a 7850
OC that Q9550 and the difference becomes negligible (of course richland can overclock but starting at 4.4 ghz I don't think it has much headroom).
