Actually I ran the F - gold, 80 wt/ R- gold, 60 wt on a track that had a very sticky traction compound and my car handled like it was on rails. The chicane was very tight, and required quick direction changes to get through it quickly. I also tried this combo with rear purple springs which worked ok on another track.
For my Purple, copper configurations I use 50/40 wt. shock oil F/R. That has been my set up all season.
Given a very high traction surface and the right mix of corners the CD3 weighs enough I think to take advantage of a 40lb spring.
I am also using a 5 cell sub C battery pack, heavier ... but i never run out of battery power.