Finally!
Maybe the answer I was looking for.
Preload will give more bump travel but less droop?
And vice versa?

But wouldn't preloading, shorten the overall length of the coilover?

Ok, I understand that regardless of how much preload is used, the spring rate will be the same. Both Linear and Progressive springs?
So with that aside...

Can't we use preload to tune how the car initially shifts its' weight?
Using my example from before, the springs won't compress till 250kg+ is put on each corner. So if we knew how much force was thrown onto the fronts when 50% brakes are applied @ 100km/hr. Then couldn't we tune it to minimise nose diving/lift/body roll? By doing this, we can balance the cars' weight out or add bais front/rear, therefore giving us maximum tyre grip?

I'm not sure what I'm getting at. I can't find the answers cause I've forgot what my question was.

Yer, I've lost the plot *cries*