Hello All, I'm heading off to college this fall. I need to decide on a laptop for college. I've decided to get my first Mac. I'm deciding whether to buy a 13" or 15" MacBook Pro. I'm also debating on upgrades, aftermarket or Apple-installed. I'm going into engineering. Some of my classes will require CAD. Also, I make money through web design via Dreamweaver, Flash, and Photoshop. I'll probably need to write papers, I'll want to keep music on it, etc. I'm tech savvy, but I've never been to college before. While I understand some of the tech benefits of the 15" over the 13", I'm wondering about the size. I'll be walking... a lot. I'll be carrying my laptop... a lot. I'm wondering how aggravating the extra weight will be. Also, I'm wondering how easy it is to use a 15" laptop in a lecture hall setting. I'm most likely getting an iPad as well, but I'm not sure I want to use it for notes.