Thanks mate, I will do and I'll report back. I've been purposely trying to do the leg contraction/arm lengthen section explosive too, if that makes sense.
It's worth learning. A few years ago I could go all out but get no faster than a 2:05 pace. My effort was high, my rewards were low, my technique was poor. Now I get reward for my effort and my technique is a lot better, but still needs work.