Don't match your riding to your suspension, match your suspension to your riding. If you are riding slow, hard suspension won't make you go fast.
As I understand it this is how world cup riders set up their suspension:
-Set spring rates to give required sag without any compression.
-Test various compression settings to establish a baseline that they are comfortable on.
-During practice, ramp up compression so they don't blow through travel as they get faster.
-Final practice and race run they should be be at max compression they need for the track they are racing. (If I remember rightly there was a test comparison between a Gee, Gwin and Levo's suspension setup in a mag a while ago and they run anywhere between 20 and 30% more compression than is available in stock suspension)
There was also an article on Pinkbike where Mike Levy rode Fairclough's demo 8 for a day and he found that it was pretty much impossible to control the bike because it was so stiff that at his normal riding pace he couldn't hold lines. He ended up having to ride way out of his comfort zone just to get the bike to come close to working properly.
This. If you arent at the level where stiffer suspension will help you go faster it will make riding your bike very uncomfortable. Also with a stiffer set up you have to be very aggressive on the bike, throwing it around and using your body as suspension.