I think most bounding exercises actually seem to have longer ground contacts than depth jumps. I don't have any emperical evidence to back this up but that's certainly what it seems like to me.
To develop top-end speed, I prefer plyos with a vertical emphasis. Also, I tend to keep the frequency considerably lower than what you're using. That however really depends on what other things you're doing in your training.
could you provide some example sof plyos with a vert. emphasis?
also you said the frequency should be much lower than what i'm doing… but i'm doing most of exersises only once/week except the tuck jumps and bounds… do you think i should drop some exersises all together?