I used to think like that, but nowadays I also think of the looks and comfort. Server/mainframe use would be all about ventilation, ease of use and maintenance, and durability. While those are important, I also wanted simple, smooth looks, and, like Bill, silence, no transparent panels or extra lights (I do appreaciate the operation leds unlike he, though). My current case, Fractal R3 fulfills nicely enough my requirements.