So, we can all easily get carried away with the upgrades but is the top choice always necessary or even a good value? Let's consider the available graphics upgrades in the 27 inch iMac lineup. The base GT 755 is a nice and capable GPU. However, the bump in performance when moving up to GTX 775M is significant (103% better performance). So, the first $200 literarily doubles your graphics power, which still doesn't mean you should buy it unless you feel you need it. Although the value is certainly there. http://www.game-debate.com/gpu/inde...9&compare=geforce-gt-755m-vs-geforce-gtx-775m Now, the next $150 spent to upgrade to GTX 780M gives a more incremental increase in performance (24% better). While this is a significant increase as far as graphic cards are concerned, it comes at a much higher relative premium. So, is the GTX 775M slow and must be upgraded? I don't think so... The performance is described on Notebookcheck.com. "The graphics performance of the GeForce GTX 775M should be almost identical to the GTX 680M, making it somewhat faster than the Radeon HD 7970M. The GPU has enough power to run demanding games of 2012 and 2013 fluently with Full HD resolution and maxed out graphical settings. Only extremely demanding titles like The Witcher 2 will not run fluently in ultra settings. Battlefield 3, Skyrim, and Crysis 2, for example, are playable at the highest detail settings." In real life performance, an average user will be able to run just about any game or application with terrific results on ultra setting except for a FEW very demanding games which will still look and play great but at maybe at a VERY HIGH setting instead. The GTX 780M will ensure that ALL games can run with absolutely no trouble at ultra setting. The question again, is the $150 premium worth such minor real world performance gain? I guess everyone has to answer that question based on their own needs/wants, but I would suggest that GTX 775M strikes the perfect balance between power and value.