well I had my retina imac for 2 years, at the time top of the range. and looking at the way things are going and the apple price going upward, also the new mac book pro with solderd ram DDR3 old skool ram. and with a new imac release next year with most likely more old tech inside I went back to PC with win10 got a 4k screen and a beast of a build PC for the same price as new high end imac. i7 6800k hex core asus edition 10 rampage M/B corsair 3600mhz DDR4 GTX 1080 M.2 Samsung pro 950 water cooled case power supply the whole works and sits at 4.2ghz and does all I need much much faster. so after having mac's since the quadra to the lampshade Imac 1.25ghz its good bye to apple. for a premium company like apple to supply old tech at premium prices I ve had enough of the way apple treats its desk top user's. and win 10 is a very good OS to boot.