So far for my hardware upgrades, I've added the larger HDD, and a stealthy USB port on the bottom corner of the front bezel as shown below.
Becoming more ambitious, I'd like to have a HDD indicator light. I am not sure where such a light could be placed on the front bezel, as I have noticed most of the inside of the case is full. There are small spaces.. but not in ideal places.
Let me know if any of you have done such a mod (Where you located the LED), or if you feel it is more for aesthetics than an actual improvement.