Unfortunately, I have a Mid 2010 MBP that is not covered under this warranty extension.
It crashes/restarts all the time with a GPU panic that is caused by the nVidia card, and triggered by the OS. It never crashed with Snow Leopard (the stock OS for my model), but ever since I upgraded, it crashes consistently (Mountain Lion & Mavericks).
I use gfxCardStatus to force the computer to use the intel graphics card. This allows me to work without random restarts.