Early on, when I’m doing this circuit, the jumps are alternate leg power bounds. The speed bounds come later, usually just before competitions or even during some of the less important meets, depending on the situation and the annual schedule.
Neither power or speed bounds can be viewed as technically similar to running in terms of mechanics, but I do agree to an extent regarding the positive effects on running form. Even advanced athletes that I have coached seemed to apply force better after starting this type of work. Slowing down the foot contact a little and getting them to feel the ground seemed to be the primary reason. That was their impression at least. It doesn’t have to be in circuit form, but it does need to be done properly.
To me though, bounds a bridge between general strength (ie: weights) and sprinting. In circuit form they can be viewed as close to SE, without the overall stress on the system. Hence my preference is to use them on the final day of a training week when this is possible.