The Evolve-X would be my choice. While CM did a very commendable job of listening to reviewers and critics and fixing any issues with either fitment or airflow vrs the original 500p, the fact that the entire front, right in front of the fans is nothing but a superfine mesh worries me somewhat. It's like a jumbo sized dust filter, that's going to look ugly in a very short while, requiring constant cleaning to keep it looking good.