Installed Sierra on 3 MacBook Pros and 1 MacPro. The 3 MacBook Pros work fine, so far Evernote is the only app that crashes when launched and a reinstall of the app from either the App store nor from Evernote.com work. Dealing with tech support on that.
For the MacPro (late 2013 editon), after Sierra install, several apps hang or are very slow even after waiting hours. Also, many apps become unresponsive even Apple's apps like iTunes, Mail,... and I needed to force quit the app. Finder becomes unresponsive frequently and after force quitting, I can't get finder back. Then I can't shutdown nor restart the computer, the only way to do it is to press-hold the power button.
Talked with Apple about the MacPro install and solution was to format the hard drive, install Sierra from scratch and then test (unacceptable at this point as it'll take me 20-40 hours to reinstall and reconfigure all my apps - lots of Photoshop and plugins, various small business software, VMWare,...) plus all of the issues with licensing companies that won't let you reinstall an app that you bought as the app is already registered and cannot be reinstalled a second time (ie: Microsoft is one that I typically have a lot of issues with to reinstall Office products).
Other solution was to restore the Macintosh HD drive from my Time Machine which is what I'm doing now. It's been restoring for 4 hours and another 5 hours to go by the looks of it.
Very happy that the MacBook Pros are working OK although totally disappointed that the MacPro install results in an unstable environment.