Threshold 2 was the code name for Windows 10 Version 1511 (or the November 2015 release). It is great to get a new version of Windows 10 on my machine but (as ever) there was a glitch that caused a little bit of work on my part.
Essentially the issue that I experienced with Wi-Fi happened again after the upgrade, the same symptoms occurred, that is the inability to access the Internet through the Wi-Fi connection. It seems like there is something in the core installation that resets the adapter to a default state rather than leaving it alone.
In other news the changes to Windows 10 seem to be based around internal speed improvements, i.e. booting a machine from cold is much quicker and the time to being able to do something useful has been reduced. Other improvements are in the user interface, some of the colours have changed to make it easer to see things like the title bar of a window (you have to turn this on in Settings though), although it would be nice to have that finer level of control for setting colours like we had in previous versions of Windows.
There a some new apps, specifically Messaging, Skype Video, Insider Hub, Microsoft Wi-Fi, Sway. All these are Windows universal apps (Metro if you like) and are of questionable usefulness; time will tell.
Overall the upgrade seems to be stable and everything that worked before still operates correctly.