Dont get caught up on "which one is faster", thats just silly. Both of them can go faster than you'll ever get up to on the average day in the trails. The real question is what kind of riding do you do? If you're a racer and ride MX tracks predominately, then the YFZ450 would have been the better choice. If you prefer trails and more "leisurely" riding, the Raptor is the better choice. If you ride dunes, theyre both pretty equal.
The Raptor has more cc's but the YFZ winds out a lot more, which is where it produces its power. As far as power and speed, they are pretty much equal right out of the box. If you just bought the Raptor 700 then dont worry, you made a good choice no matter what kind of riding you do. The Raptors require less maintenance as well, the YFZs generally need to be rebuilt more often, so thats something else to consider. All in all, theyre both just as good.
2011 F6 Snopro - its green and moves best on snow.