The direct comparison on the Apple website has the 2.33 Core2Duo as about 35-45% more powerful than the 2.16 CoreDuo. And for Logic, we're talking about a 240 reverb plugs at once vs. 165. That's a pretty major increase in power/performance.
Here's the link:
http://www.apple.com/macbookpro/intel.html
I love my 2.33 Core2Duo. And get the 15", NOT the 17". The bigger one is just a little too big to be truly portable. If you need more screen real estate when you're at home or in the studio, get a cheap external display. This way, you can get your new MBPro for only $2344, and you have a truly portable laptop with no sacrifice in power.
How's that for splitting the difference between your two options?
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2.33 GHz MBP C2D
Logic & Reason, with as much divine inspiration as I can muster.
"A melody is like a pretty girl. Who cares if it's the dumbest in the world? It's all about the way that it unfurls..." -MF