I don't like the new scrollbars. They are black, so screaming in your face where i never happened to notice them (Outlook has them all other the place on my laptop). And the design is narrower, so makes it harder to point and click, although maybe target area remained the same. Still, affects mentally. And for what? Prettiness.. I also don't like all office apps be similarly bland, but if i enable colors, there is now a huge blob of blue or green at the top and even in your gif above you can see how everything moves down a notch when new design is applied, which means a bit of less space for actual content. Not nice. The only good thing is that you moved away all the buttons and indicators from the titlebar (i would also get rid of huge search field), so now it is a bit easier to grab and drag windows around without fearing to click some button instead.