Of 4 mac's I have been responsible for purchasing, 3 have an ATI GPU and 1 has an Intel GPU. Not a single one has an nVidia GPU.
Good for you. But still, all Macs today come standard with an nVidia GPU, and some only have nVidia options.
For SL at it is.
That ATi is an AMD brand and a competitor to Intel.nVidia is an nVidia brand, and Apple uses Intel chips. What's your point?