I finally did the upgrade to Windows 10 Threshold 2 (the previous install was Threshold 1) last night, everything went really smoothly without any serious glitches, first impressions is that the latest major update to Windows 10 is a very zippy OS, I have encountered none of the issues that other people have complained about, this new installation works and seems to be really stable, what's more, I didn't have to go and download any drivers from the Dell website, Device Manager is reporting that everything is operating correctly right off the bat, one of the new features of Windows 10 Threshold 2 is Cortana, you can think of Cortana as being a virtual personal assistant, ask it anything you like and it will come up with answers, at the moment I don't have Cortana fully set up but am working on it.
The updated version of Microsoft's Edge Internet Browser seems to work really well, I'm still on early days with the new OS though.
All in all, I think that Windows 10 Threshold 2 is a much better OS than either Windows 8 or 8.1 was, big improvement, gone is the Windows 8 start menu that took up the whole screen and needed clicking on the Desktop icon tile just to get to the Desktop, it has been totally replaced by Windows 10's more familiar start menu, and Windows 10 Threshold 2 boots straight to the Desktop.