I knew retina has it's toll on the gfxcard and that iMacs don't exactly have powers to spare in that department, but I definitely hoped for a better experience than this. I just got my maxed out iMac 27 inch late 2015. The only thing not being maxed out is the gfx card as I felt it wasn't worth the huge step in $$$ to go from 395 to 395x. I still have the next to the best gfx available after all in this machine. Although the screen is gorgeous and even more gorgeous when put into scaling mode, I noticed very early on during my tests that there are repercussions to retina. Just downloading Evernote and opening the todo-list for my iMac-tests revealed issues. Scrolling the note of about 2-3 pages was somewhat laggy and slower to respond than my old machine without retina. On to just scrolling through a pdf quickly and again: it is oh so clearly worse in performance. So bad actually, that it looses that magical "mac feeling". Scrolling in Chrome and Safari was fine so I was lead to believe that good scrolling needed programs with gfx acceleration in use. Just a speculation, might be something else. Is this something that you notice? I've googled a bit but haven't found a huge number of threads. They are mostly about the macbook pro's and rarely about the iMacs. Maybe my demand of having at least equal performance is high when taking retina into the picture and maybe I'm letting things bug me that others won't take note of but really, as it feels now, this computer is going back to Apple to await the 2016 model.