I happen to have BOTH the Zero Gravity Double Bubble, and Sport Touring Windscreens. I love the ST, because its tall enough to get the wind at/above helmet level - I am taller than the average rider, and the stock and mostly the Double Bubble push the wind right at my neck, which gets a bit chilly in fall/spring. The Double Bubble is very cool, but only slightly taller than stock (on the order of 1/2" or so, based on my semi-crude measurements).