iMac 27" core i7 3.5Ghz / 32GB RAM / 512 PCie SSD - GTX 780M Google tabs still sluggish when opening new one. Office 2016 maximizing is also jerky for example. Fresh installation here. Not sure what's the deal... The OS itself is snappy but the transition between apps, maximizing apps ( not full screen ) is jerky. Not fluid at all.