I'm a PC user and I'm thinking of switching over. I've had limited experience with Macs over the past 2 years or so, mostly with G4 desktops. I'd be using the computer mostly for Adobe and Macromedia programs: Photoshop, Illustrator, Flash, Dreamweaver etc. Anyway, the computers I've been looking at are the dual 1.8GHz G5 with the dual 512 SDRAM upgrade, and the 15" Superdrive G4 Powerbook. I know I'd be sacrificing some performance for portability with the laptop, but I was just wondering how significant a step down the G4 powerbook would be? My biggest concern is with performance while running multiple programs simultanously. On my POS PC, I can't even run Illustrator and Photoshop at the same time!