I currently have the Antec 900. Whilst it was an amazing case in its day, it no longer fits modern hardware. I've drilled about 4 holes into it, and I also have the hard drives teetering over the edge. The cables are packed so tight that there is minimal airflow. I had to remove my Graphics Card last month, and had to remove 5x Hard Drives, DVD drive and Modular Power cables just to get it out - and I still had to do some Tetris Shuffling, it wasn't a clean removal.
A new case would allow me to improve my airflow, run a cooler PC and ultimately prolong the life of my hardware.