Well, the point of using luxrender is to get more realistic lighting and thereby render materials in a more realistic fashion.  I didn't see anything on there that talked about the controls for controling the lighting other than the one screengrab that showed controls for sunlight.  Nothing seems to be shown about using mesh lights.  And the materials in the sample images didn't look as good.  Which seems to imply that it requires more tinkering to get stuff to look right than reality requires. 

And the controls look much clunkier than reality's controls. 

 

The only advantage would seem to be a lower price point, but you're losing out on the features in reality.