raining on the sport chrono parade
Judging from this board, sport chrono is regarded favorably and is even considered a must-have option by some. Personally, sport chrono strikes me as a childish marketing gimmick and I would never choose it off an option list. Sport chrono claims to offer three "performance related" features: a manual stopwatch, a sharpened throttle response, and now the 997tt overboost. IMO, those features are designed to appeal to amateurs and offend serious drivers. First the stopwatch. Nobody believes manually clocked lap times, that's why race cars have transponders and data loggers with gps and accelerometers. Deliberately buying a manually activated stopwatch for your car instead of an accurate timing device marks you as an amateur. And it's hard for me not to feel let down by that ugly dashboard pimple when Porsche could have easily provided a full Motec-compatible data logger instead since all the sensors are already in place. Second the throttle response. Skilled drivers would like as much control over their controls as possible, so they prefer their controls to have linear responses. Amateur drivers would like to have the illusion of more power than actually exists when they crudely stomp on the accelerator pedal, so they enjoy the "sharpened throttle response" that makes their car more difficult to control. Third the overboost. To my mind, it's straight out of a 1980's arcade video game. Push the button to momentarily get more power. Pretty soon we will be mashing the overboost button all the time and then we will get "overboost thumb" just like on a video game. And if people are willing to pay for that, Porsche will offer us an "overbrake button" that briefly gives improved braking power, and an "overnav" button that lets you find a better route once a week, and the amazing "overloud button" that briefly lets you crank up the Bose volume from 10 to 11, and so on and so on. And if we all buy those astounding features, then Porsche will take it to the next level by offering powerups that we can drive around and collect. Fill up your car with Porsche-certified gas and they will give you an extra 2 hp for the entire tank of gas. Park your car in a Porsche-certified garage and get an extra 1 hp for the next 24 hours. Service your car at the Porsche dealer and you will get another 5 hp and 2 mpg until the next service interval. And yes, the powerups will be cumulative so you can stack up the bonuses for truly eye-popping power and efficiency. Why can't Porsche just design the system to give you the most power it can whenever it can? Or offer true gps-based telemetry so you know exactly how fast you went where and what you need to do to improve your times? Why do they give you these absurd manually activated capabilities? The only answer that I can make sense of is that they are marketing the package to people who haven't yet realized that extra is never really extra -- it's just a deceptive way to start you with less. By offering an overboost feature, Porsche is just cheating us out of the boost that we should have gotten all along. So no sport chrono for me.
The sharpened throttle response fixes the problem for heel and toeing when Porsche made the gap between the pedals wider than the 996 in the search for more legroom. And many believe the car throttle response should be that way as standard. 
A little hint: sport chrono also has an influence on suspension mapping, engine mapping, AWD mapping (electronically controlled on the Turbo), Tiptronic mapping, VTG mapping, PSM mapping, etc. etc. etc. And although many people don't seem to understand the overboost function and think this is just a way to rip off customers, I have to disagree. I had the overboost feature on my very first Lancia Delta Integrale and believe it or not, it is a lot of fun and helps to keep the engine and drivetrain parts in a healthy shape.
I was a mere lad back in early '90s when robo-cop S-Class came out at $92Kish base price in midst of early '90s recession. 
