I have a x9 but I don't have any experience with a xo. From what I have read the xo is slightly better than a x9 but for the price I would't buy it. Get a x9 and some flak jacket cables or somthing similar, cables make a big difference. So if you don't want to pay xxx more for bling, weight savings, and slight peformance increase stick with a x9 and some good cables.