The ZPS3 (as well as the previous ZPS') simply adds more resistance making the trem more likely to go back it it's set zero point (hence the name). While it in theory will make the trem more stable, it's all about setup. It works under the same principles as the Hipshot Tremsetter.
Yeah if any body should have neg'd me it should have been you. its funny that he left his opinion about my "opinion" , and expected me to care. Your cool dude, hows sweden is it realy as gloomy as they say?