Quartz 2D vs OpenGL ES Learning Curve

Question

I have been developing iPhone Applications for a couple of months. I would like to know your views about the Quartz vs OpenGL ES 1.x or 2.0 learning curve. You can tell your per

Answer 1

I skipped Quartz and went right to OpenGL ES. I started with a 2D sprite based game. Thought it was pretty easy.

The key is having a good example to look at. I used the Lunar Lander clone (Crash Lander), but I don't think that's easy to find anymore. Maybe someone who has done it recently knows of a better, newer example that uses current best practices.