Modulating reflections with the diffuse light node makes no sense at all to me, at least in real world terms. (That's why we should never use Reflect_Lite_Mult in the PoserSurface node, which effectively does the same thing to reflections).

Personally, I would avoid it for that reason alone.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)