Now I suppose you are wondering: "Does it actually make a difference to the running temperature?"
Answer: Yes and no.
The main difference between the casefancasefancase... and any normal case is the system or mainboard temperature. After prolonged use it remains pretty constant at about 23 - 24 degrees Centigrade. The CPU temp is not as greatly affected, basically because I am using the standard fan/heatsink supplied with the CPU. If I was to shell out for something with big copper fins on it I'd probably notice a difference. But just in case you were wondering, here's a BIOS screenshot.