ummmmm... no. it makes it extremely easy to push the limit. but doesnt make it actually perform better, it just makes bad driver's able to drive quickly and pretend to be a good driver. a good driver in a real sports car would be able to get the car to do what he wants in a corner, and know how not to let the car go into a big push or oversteer.
i have driven an evo 10, and i was able to go into corner's in such a bad way and the car would still sort itself out and end up doing the corner perfectly stable, nomatter how much i tried it was extremely hard to get the car to become unsettled. some may think thats cool, but i think its fucking lame. if you have a sports car, you should have the skills to drive it.
and automatics may take away skill, and ill agree that auto's are lame as hell. but shifting is not really a hard part of driving, its something any good driver master's and it becomes second nature. Braking, cornering, controlling the balance of the car, the switch between brake to throttle, etc... are all much harder than shifting.