Thanks for this feedback. The App Store's little Install button is tempting.You're not missing anything, believe me. I have top-end iMac with SSD, and Sierra so far is nothing but slowing down, freezings on sleep/wake and 3rd party software compatibility issues. I suggest everyone to wait at least for 10.12.1 or even 10.12.2
I may not update my 2013 MBA at all until I'm set up for production on a new mac. My current setup is so stable.