I will be be buying an iMac this week to replace my mid 2015 15" Macbook Pro as desktop replacement. I'm not a pc gamer. My usage is light to medium, and using Windows 10 Pro sometimes via bootcamp or VM. The specs I'm looking at are: 21.5" iMac 4k $2199 - i5 3.1GHz - 16 GB Memory - 512 GB SSD - Intel Pro Iris Graphics 6200 27" iMac 5k $2399 - i5 3.2 - 8GB Memory (I will be adding a 16GB kit) - 512 GB SSD - AMD R9 M390 The 21.5" iMac is ideal for me, but the 27" iMac is tempting. Please recommend which one I should go for.