Ive had the springbaks for 2 months now...it mightve increased my vertical by an inch or so but more importantly i can definitely feel less stress while i'm sprinting or jumping. 25$ is a bit pricy for a pair of soles but id recommend it. and redsoxfan do u kno if weight plays a factor in the effectiveness of springbaks? cuz i only weigh 135 so maybe thats why i only got an inch out of them