Just be careful thinking stiffer is better. You can FEEL like the bike is going faster on a stiff suspension, but, the traction can be taking a dive at the same time. Appropriately (and quickly) compliant suspension is always faster...it allows the tire to spend the maximum amount of time on the road. That's what I despised about the stock rear...way too stiff, while being way too slow to compress on bigger bumps.
On one particular turn, which has a bump just before the apex, I went from being squirrelly at 40 mph (and dangerous at 50), to smooth at 80 mph and do-able at 95 mph. A used Ohlins rear shock that is appropriately compliant, as well as allowing much quicker compression, was the only change.