What an interesting video. The Performance Z is soft. However, after putting spacers, it is a bit bouncee...
My take on these upgrades is: if you are going to drive your Z as a daily driver only, why spend so much money on addons. I already have to be careful not to get a speeding ticket with the power as it is. If the car is not going to be taken to a track, why the need for more power.
The only thing I will definitely add is different exhaust and wider tires; eventually. Once the ones it has have to be replaced.