The only thing that really impressed me is Adobe Flash performance. Some sites still use it for video content and there is a noticeable improvement in performance. Other than that, it's not really that good as I anticipated reading the positive reviews here. Yes, I understand that this is not the final version but still. It's an improvement over Yosemite but just because Yosemite was that bad. Basically, it's how the Yosemite was supposed to be I guess. Preview and PDF: Instead of lagging on scrolling trying to process all the stuff it just does it in the background and shows a blank page first. This is how it should have been from the start. Split view: I thought it would be like it is in Windows, just drag the window to the left/right, but it's done in a very counterintuitive way (I had to use Google).