I've said this before in numerous forums, but here's my .02 on footstrike.
I don't believe that what part of the foot strikes first is as important as where the foot is in relation to the center-of-gravity.
Faster and more-efficient runners tend to have the foot impact right below the center-of-gravity, sometimes a little behind it.
Slower, less efficient runners tend to have the foot impact in front of the center-of-gravity, which causes more knee problems and causes a "braking" effect upon impact.
Having your foot strike under COG or behind will often accompany a midfoot or forefoot strike, and having the foot strike in front of COG will almost always accompany a rearfoot strike.