Didn't want to wait any longer for 2012 iMacs so I instead went for the current gen. LOVE IT. While it stated that I would recieve 4 gigs, it instead came with 8. However, I had already ordered 16gbs from macsales. I threw in 8 gigs from owc and left the stock 8 gigs. Works fine! However, do you guys think it'll be better if I instead used all 4 sticks from owc? Not sure if mixing and matching ram will effect performance in anyway. Thanks!