I wouldn't say that...
only with OC I'm experiencing real, no laggy N9...
FasterN9 script made literally nothing to my N9, except for some strange mishaps like Messages app opening in intolerable 4 or 5 seconds, toggles in status bar working incorrectly, etc...so I got rid of it
now I continue to use my N9 @1.3GHz as with previous core version and it's all good...