I'm using the Quadratic fall off on my Lights. This was causing some severe ' burn out ' in my renders. A friend of mine pointed me in the direction of Linear Workflow. Which I'm still not 100% clued up on. But the basic idea is that you have to gamma correct your textures in order to get a more accurate render. Check out the difference in the Renders here. It's giving me a much cleaner fall off, and the burn out has gone.