I wouldn't *only* use GI_Joe. I would use it to first light the scene giving everything the desired lighting effect, then go back and use other lights to achieve different effects. It's definitely doing more than what is needed I guess, but that's what I would do.

So many times in animations I do, I think I have a scene lite properly, but get into the animation and realize that some sides of objects are completely black because no light can reach that particular area. GI_Joe does a good job at preventing this. I usually have it just bright enough to make everything visible. That's all its purpose is - to make everything visible.