I wouldn't say the 4690K would blast away the 4670K. They're pretty much equivalent except for the 100MHz boost in the 4690K (stock and Turbo) and the fact that the 4690K will overclock much better than the 4670K. The thing is, both will run Dolphin excellently. The 4690K just happens to be more excellent.
Having said that, if you don't own a 4690K, get it instead of a 4670K. If you have the choice between either one, there's no reason to go with the 4670K since it's technically inferior.
Having said that, if you don't own a 4690K, get it instead of a 4670K. If you have the choice between either one, there's no reason to go with the 4670K since it's technically inferior.