I went through the sub-forum and don't think a thread had been created for this yet. I'm curious to see how many people are involved in the Developer Preview / Public Beta or have chosen to abstain. Personally, OS X Sierra is the first release that I so far have no real interest in beta testing, just because on the face of it, there's not a whole lot new beyond Siri integration. OS X 10.11.6 is extremely rock solid at this point, so it doesn't make sense for me to sacrifice stability for a feature that, even on the iPhone, is honestly pretty crappy. Beyond basic queries related to weather and setting alarms, Siri is horrible at understanding the context of a question. I barely use it on my iPhone for this same reason. The second biggest feature is the ability to unlock with Apple Watch, but how many people actually own one of those? I suspect this is part of a bigger push for some sort biometric authentication on the Mac in the future. Maybe the ability to use a native finger print scanner on a keyboard or mouse. Thoughts? Are you going to beta test or not bother with it?