Its best not to use it for any maps for now. It is very costly on some and even messes up other graphical options on lower end pcs.
It could simply be fixed by making it a clientside option to disable it automatically for the low end users and only allowing players who can see it to be rendered.
In the case that its just one for something very specific I wouldn't mind using it myself but only to a small limitation as it renders the shadows poorly unlike portal 2.
Poll
