I'm buying a new 15" Powerbook. I'm a DJ and Photographer so I work mostly with DJ programs and Photoshop - and sometimes Illustrator, Soundtrack, Peak, Garageband, and of course iDVD and iMovie. When I'm DJ'ing in the club I usually play songs off my internal hard drive, and I play fro 8hrs straight (will there be heat issues?). Should I buy the 5400 120GB, or the 7200 100GB. What's more important? The extra 20GB or the extra rpm's?