Apple seeds sixth beta of macOS Sierra 10.12.2 for developers
Apple on Thursday released another developer-only macOS Sierra 10.12.2 beta, the second one in three days, and the sixth overall.

Release notes accompanying Apple's new beta offers no information about what the updates include beyond maintenance-related changes and minor bug fixes. The short cycle on the macOS beta, similar to the frequency of iOS beta updates, suggests that a release is imminent.
While mostly consisting of bugfixes, the update also includes the same emoji featured in the iOS 10.2 beta. These match the Unicode 9.0 standard, and offer both new and redrawn icons, the latter with more detail.
The last macOS full update, 10.12.1, was released to the public on Oct. 24
The last 10.12.2 beta had references to a trio of new GPUs, but no solid data on any of the three.
Developers can download the latest beta releases from Apple's developer webpage or directly on test devices via Software Update. Public beta participants can get the software as an over-the-air update if they're already registered in the program.

Release notes accompanying Apple's new beta offers no information about what the updates include beyond maintenance-related changes and minor bug fixes. The short cycle on the macOS beta, similar to the frequency of iOS beta updates, suggests that a release is imminent.
While mostly consisting of bugfixes, the update also includes the same emoji featured in the iOS 10.2 beta. These match the Unicode 9.0 standard, and offer both new and redrawn icons, the latter with more detail.
The last macOS full update, 10.12.1, was released to the public on Oct. 24
The last 10.12.2 beta had references to a trio of new GPUs, but no solid data on any of the three.
Developers can download the latest beta releases from Apple's developer webpage or directly on test devices via Software Update. Public beta participants can get the software as an over-the-air update if they're already registered in the program.
Comments
I haven't experienced many although using dual screen on a new Mac Pro I have seen some oddities such as momentary black outs when dragging images from open apps on screen two to open apps on screen one and a few times the Finder views don't update requiring Finder reboots. A few Mail glitches also but zero beach balls.
Talking of dragging images ... I wish Photos would support drag into onto apps' icons the way everything else I use does. It supports drag onto Pages and Numbers and Keynote but nothing else such as Photoshop.
Beach balling does happen though.
In general im lacking yhe warm fuzzy feeling of the initial release.
But it is still slower than I'd expected. Hopefully a few optimizations will help (and maybe a clean install later on!)
Have a nice day
You lose brownie points for typing MacOS instead of macOS you know!