I raised mine on my B12 about 10mm initially. It definately quickened the steering. After performing the stage 2, exhaust and gearing down, I raised it by about 3/4"! This definately quickened the steering, made the bike much more 'flickable'. And helped keep the unintended wheelies under control.
You certainly won't hurt anything by adjusting them. And you can always return them to original height. Just take some time and get used to the new handling, as it will feel like a different bike.