First of all getting official update from preview builds and expecting same performance like single direct official update? Not for me then...and most of cases that I know...last year's dev preview program teached me this.....i had Two Lumia 520s and both behaved differently while scrolling with background image applied.... The one with devp preview and the getting official cyan used to shutter a lot while the one with direct cyan scrolled really smooth. And to be sure I reverted the shuttering one to WP 8 and again updated to cyan and guess what? It was fixed so.....it does affects....cant tell you how....but just feels different.....