Fitted this to my car this morning and there is a noticeable increase in responsiveness, smoothness and power probably due to the first two things, I've read a lot about them and I have also cleaned all the grounds I can find on the car before (edit:- 2/3 months ago), but this really has made a difference, no placebo effect, I know how my car drove before and after and I also did not disconnect the battery so didn't reset the ecu, I have grounded both heads, the block, the alternator and the throttle body
just thought I would share my findings, will give an update after a few days if anyone's interested 😀