I'm trying to pick between the 15" and 17" macbook pro for my next computer. I am studying electrical engineering and computer science so I need it to be able to handle a lot at once, run CAD programs and basically just be fast and reliable when handling heavy computer stuff. I'm new to the fields, and I need some advice: 4GB or 8GB RAM? Upgrade the processor? Why? 500GB 7200rpm or 750GB 5000rpm Recommendations/thoughts on the screen upgrades would also be appreciated. P.S. I know a lot of engineers who hate macs and bash them regularly, but I prefer them and have done just fine with my old macbook, but I need to upgrade to something more powerful and tailored to my need.