I'm looking for some advice on using a Mac for CAD. Is anyone out there using a CAD system with a MacBook, or is it going to be something I absolutely need an MBP for? On screen size alone, I'm thinking MBP, but then a MB with a separate display for home use would also work. I've heard the 4gb MB is fine for heavy photoshop and I assume that a CAD system will be the same draw on the RAM/video?? Any advice or experience or tips would be much appreciated.