There are still many rough edges in the new OS but overall I am really excited about the visual direction that Mac OS X Yosemite is taking. It demonstrates a more mature and subtle approach in adapting iOS 7 design language. No ultra thin fonts, no crazy parallax, no ridiculous icons, just subtle use of translucent materials accompanied by a bright and cheerful palette. Using the new OS feels fresher, exciting, and more modern. I am looking forward to exploring other design changes in the the new OS that I may have missed. I'm definitely pleased with the design direction Apple is taking OS X into, despite the fact that as it currently stands it's clearly still in flux. We're in beta, though, so that's just fine. The two biggest issues to me are one, that text input fields and buttons are not visually different, and two, that neither of them get any mouseover effect whatsoever - both cursor and button/input fields remain exactly the same. Something else I've noticed: is it just me, or does Apple use a different theme on-stage during a keynote than what actually ships in the beta right now? The transparency and colours pop way more during the keynote than while using the beta. Odd.