I try to use the 3 light setup whenever I can, but you have to look at the scene and consider what it needs first. For an outdoor scene the 3 light setup is perfect....barring things like torches, etc.

Let the scene dictate the lighting.

As far as all those fake GI plugins, they never impressed me either, but MR does! But then again PRMan 11 will have GI, caustics, etc. too and that's due soon It's all a matter of personal taste. There's plenty of room for all sorts of render types

Darkon