slow as in you maybe go 3/4 to the floor, it goes a little bit, then it gets a kick in the pants a lot later than planned , it just seems to hunt between gears a lot. it seems that the response is always a bit behind what the pedal is doing, especially from a stop.
it's a drive by wire system. the benefits of it are that it starts off 'slow' to protect the drivetrain from unncessary wear. however, if you 'punch' the gas, the car should go.
the other advantages of a drive by wire (means no cable to throttle- computerized input) are that if the stability system detects a discrepancy between wheel stability and driver input, it will passively attempt to minimize this by 'cutting' your throttle input.
what this means, ideally, is that if you are driving on a dry road in ideal conditions and you overestimate your speed into a corner, and then further over estimate by applying throttle, the system- theoretically- will cut that input in the interest of maintaining stablility (my understanding is that ATS will apply brake, but only if driver starts the cascade by braking). however, you can still drive the car into a wall... it'll just try to 'disuade' you from that.
the downside of this system is first and foremost what you mentioned. the driver feels like they need to 'push the gas more' to get the same response (diminished responsiveness) from a wired throttle system.
another downside is that the system may, potentially, malfunction.
you can prove that you have this system by 'punching' the gas in park. the needle on rpm will hardly move.
i have an 02ls and an 04. when i first drove the 04 i thought there was something wrong with it because i had to depress the pedal so much to get it to go. but, there is a point at which when you go that far, it will bolt. if you have that point, it's prolly normal, if not, maybe something wrong.
hope it helps!