Originally Posted by Joshboody
Air density is always more powerful then mechanical advantage, BUT both is even better. The CR limits are because of knock, but DI allows higher CR (less knock) so you really can't compare to PI.
Yep, the thing to keep in mind is that CR will always be there regardless of RPM(I know, I know dynamic CR changes a little based on numerous factors but this basically holds true.) So that means you can help to offset poor off-boost performance by running a healthy CR. It also increases fuel mileage.