Playing from a high-speed HDD eliminates "pop-in" textures often seen when reading from the DVD drive.
By extracting the game files, users can theoretically swap textures or modify vehicle physics, though the Just Cause modding community is significantly more active on the PC version.
Running Just Cause on a JTAG or RGH console bypasses the standard Xbox 360 security layers, allowing for features impossible on "retail" hardware: