Not true, I posted this link in the other thread, but I'll post it here too:
http://content2.eu.porsche.com/prod/boxster/boxsters.nsf/papenglish/chassissport_chrono
"When ‘Sport’ mode is selected (using a button on the centre console), the engine management system applies a modified throttle map to achieve a racecar-like engine response."
and according to this:
http://www.izoom.com/auto.aspx?article=2006porschecaymans.html
"In Porsche's runs on the Nurburgring, a Cayman S equipped with Sport Chrono was three seconds a lap faster."