I tried going from an iMac 27" to a 15" MBP last year and just couldn't do it...I'm a photo/video guy and I need the screen real estate. That said, I really want some portability..I don't mean the "I'm going to a Starbucks" portability, but the kind where I could safely bring my computer to work for 2-3 days...Or somewhere else for a weekend. These machines are so light, weight isn't even an issue. It's just protecting it..I also use them for tethering in the studio (with my camera). I might downsize to a 21" to maybe make this less of an issue. Maybe get a 13" iPad so use as extra screen real estate too. Any help? Thanks!