Q: Car nearly stops while driving and not performing well

My car is having performance problems. Recently, it began to nearly stop while I was driving. It was as if only 2 or 3 of the cylinders were functioning. After pulling over to the side of the road, I turned off the engine. Then I waited a while and restarted it. It ran normally and no engine lights came on. I called the dealership and was told not to be concerned about it. I can't do any better than 6.5 to 7 seconds 0-60 time, in S+ or S mode. Of course, I'm not trying to drag race or anything like that, but I feel a car should have the power to burn off rear tires if the ESP is disabled. When the ESP is off and I floor it, there is not a single chirp from it. The transmission is jerky and has the feeling like it is slipping. I was told that this is how these transmissions feel. I am hoping that is not the case, because it does not seem normal to me. The car makes a great noise, but it just doesn't seem like it is performing like it should. Do you think that the computer is causing a problem or what is your determination of my car’s problem?