Honest to goodness the results don't seem worth it for the power usage. Pre-baked lighting, environment maps, material shaders look _really good_ and are easy to get decent frame rates out of without sacrificing artistic freedom. Why are we making it more difficult for ourselves with global illumination which just introduces more problems. It's just very difficult to realistically light things while still maintaining high-visibilty of game assets in dynamic situations.

It sells graphics cards but I just don't think it's very practical.