Hi there, I'm a long-time reader and forum stalker but now I need some help deciding which iMac to buy. I can't decide between this refurbished 27" iMac http://store.apple.com/ca/product/G0MS5LL/A/refurbished-imac-34ghz-quad-core-intel-core-i7 Which has the GeForce GTX 680MX graphics chip, 1TB Fusion Drive and Core i7 upgrades or if I should pay the extra $200 (with education discount) and get a brand-new 27" iMac with the GTX 775M graphics chip, 1TB Fusion Drive and Core i7 upgrades. It's really the 680MX vs 775M comparison that concerns me. This will be a computer for gaming and school work. I study cinema and will need to produce movies. Upgrading to the 780M will be stretching my budget just a bit too far. Thank you!