Assuming that the sport shift mode is driven perfectly, is it faster, slower, or the same as having the car in just regular drive D when accellerating?

I am refering to the IS 350 also if that matters

 

I find the sport mode a little slower. You still have a slight advantage with the paddle/shifter than the sport mode automatic.

 

I would think that manually shifting would be faster...BUT, with the shift delays in Sport mode, it's difficult to time your shifts properly. For this reason I think full automatic is the way to go.

I've tried both many times, and believe me, it's hard to tell EXACTLY when the IS will shift when you're manually shifting. I wish they had a fix for this. (ya ya, a REAL manual transmission for the IS would have been nice).