The mega droop setting seems to work well for low to medium grip tracks but requires a smooth racing line, it doesnt seem to work as well for more aggressive style driving.
We have also had a lot of success with no droop, and really hard springs (22-24lbs) it really makes the front tyres work very hard.
We dont run on carpet here unfortunately and none of our tracks are really high grip so it will be fairly different on carpet I would say.
Also one thing I tend to run and seems to work for me is about 1mm ride height, I have found that the chassis doesnt realy scrape very much at all and with the lowered ride height you get more camber on the front wheels which seems to give it much more steering. Makes it great in the tight twisty sections.
tp