I have an amazon gift for $500 and I'm trying to decide between purchasing the 13 MBP(non-retina) dual 2.9 or the 15 MBP(non-retina) quad 2.6. I only use the computer for e-mail, surfing the web, MS office, recreational photo editing and ripping the occasional DVD through Handbrake. Is the 13 MBP (non-retina) dual 2.9 enough or should I pick up the 15 (non-retina) quad 2.6. Thanks is advance for your thoughts.