I currently have a 2012, 2.3GHz Quad-core i7, 1TB Fusion, HD4000, Mac Mini with a 27" Thunderbolt display. I'm thinking about selling my current setup and going with the new 5k iMac, 3.5GHz Quad-core i5, 512GB SSD, and M290X. This upgrade would primarily be for the retina display. This computer will mostly be used for web browsing, grad school homework, Microsoft Office, facebook, and a little photo/video editing of my personal stuff. What are the pros and cons of these two setups? Will I notice a significant speed difference between the two? What about the difference between the HD4000 intergrated graphics/27" Thunderbolt display vs. the M290X/5k screen. Who should consider upgrading to the 4.0GHz and M295X? Would I see a benefit to these upgrades?