i haven't got it so i can't tell you to buy it or not but you should be good.
amuffin wrote :
The core 2 quads do surprisingly well in BF3, especially the Q9400. However, in the mean time I would overclock your E8400. BF3 loves multicores and an overclocked Q9400 or E8400 will do nicely
Though do you have any Q9550 or 9650's available?
but amuffin thinks so and i do at times trust his judgement.