I am thinking about buying a new MBP and plan on getting Aperture 3. Besides the GHz difference the main issue is the i5/NVIDIA 256MB v i7?NVIDIA 512MB. Is the boost in Intel Core and graphic MB worth the $200 difference? I will more than likely be getting more RAM and going with 8GB, so I am looking at trying to keep some of my cost down-which seems to keep climbing every time a click on another "upgrade!" Thoughts and advice gladly accepted.