Sorry, you are right, vitters -- My Bad! 

Yes, the question was in reference to the map scale slider in the Firefly Render Settings in P6.

Kinda surprised to see that one was subsequently removed.   I use it quite a bit during test renders as it does appear to greatly reduce system demands & speed the process along.    But... I've never actually compared two side by side, so... now I'm wondering if I've just been kidding myself.   DOOH!