As long as you aren't talking about 3D graphics, the MB C2D is definitely faster. I have one co-worker with a first-gen Macbook Pro and another with a first gen MB (white). I have worked on both many times and I have to say that my new BlackBook (2.16 C2D) is noticably faster at many things. Macworld has benchmarks on all of these in their review sections. Just going off my own feel, I think the C2D makes a difference.