Shortening shifting time

Reducing the shift throw and gaining a better shift might be noticeable on the track. On a street car it is more likely to cause a longer shift time due to the precise gate locations and the time it takes to find them. Also look at the time reduction they are quoting. 35% of what? Say it takes you less than two seconds to push in the clutch, stab it into gear and release. The clutch time alone is going to take longer than the shift. So lets say you going from 2 into 3 takes 1.5 seconds. 35% off of that isn't going to make any difference because the clutch itself doesn't release and grab that fast.
Now if your car has a well built engine, new transmission with proper gearing and a competition clutch a short throw shifter makes a bit of sense as it would now be the slower part.