I've heard both stories as to why blowholes are good and bad. Bad because they divert airflow from the CPU and good because they eliminate the hot air that could get trapped in the top of the case thus increasing overall case temp. What about putting in a fan that actually sucks air from the outside in from the top? To me, it appears this would fix both problems. It would increase the airflow in the case thus adding to the airflow used by the CPU and it would eliminate hotspots but "churning" the air up at the top of the case... Is this correct or should i go back to physics 101.