I use box jumps all the time. (Not really). I do use them once in a while. Why? HIP FLEXORS. I'm a hurdler, vert isn't too important in the event because your center of mass is supposed to stay at nearly the same height throughout the event. But, I would never bother trying for crazy high box jumps. I get enough hip flexor work from tuck jumps and the occasional set of ~36 in. box jumps. Aside from that, I really see no benefit in it. Even then, how many events or sports actually require that kind of hip strength? Hurdles are the only thing I've ever done that have actually required it.