Go with Ballistix or Geil Ultra Edition, they are both kick ass rams, nothing touches their quality. XMS isn't all that great, bot much performance boost to tell you the truth. Go with the above, they are great!
No OCZ is not!!! ARG, why oh why. BTW, Corsair isn't worth it. Go with Geil or Ballistix, nothing else. The Corsair Low Latency XMS is the only really good ram they make, the rest are mediocre at best.