Actually used an ASUS GT550 TI 1GB GDDR5 instead of the GTS 450. Great performance. Can max out Tribes Ascend, Left for Dead 2, Skyrim, and Arma II:Combined Operations.
The case is great with the external SATA connection on top for 2.5 and 3.5 HDD troubleshooting.
OC to 4.2GHz and temps are about 27-30c idle, and never reach above 50c.