I’m really not sure, all I can do is speculate. I used it senior year of high school. My PR dropped from 15.0 to 14.6 despite missing the first half of the track season as well as being injured 6 times that year. I speculate I could’ve broken 14.3 without all of those injuries, of which several were severe and required an MRI. I think a 14.6 was pretty decent for myself considering that my 100m time was probably only around 11.7 at the time. I don’t know whether I would consider myself lower level…or higher level for that matter. Getting so many reps IMO is the best way to attain efficiency for lower level hurdlers. I think if you do the workout that I said you should GRADUALLY build up the volume of the workout each week and do it CONSISTENTLY to avoid injury. Whenever I did that workout, I would focus on one aspect of technique at a time. Whenever I had my next hurdle workout, I felt like my body was on autopilot over the hurdles. It felt automatic. I think it can be useful, you just have to be careful about how you implement it.