I currently own an early 2006 MacBook 1.83 Core Duo + 2GB RAM that's connected to an external monitor and I was wondering if it was time for a switch. I work as a web developer, but also use Photoshop for designing. If I make the mistake to have both PS and Aperture open, then the Mac becomes incredibly slow. I also have Parallels running Windows from time to time for testing purposes, which again slows my productivity down. So is it worth upgrading? How much of a difference are we talking here?