It is now possible to run multiple instances of Metro applications. They're also capable of being resized. All of this is functionality we should have had from the start, but again, it's nice to see Microsoft catching up in that regard.

You thought I wasn't going to rant? Well, you thought wrong.

As you can probably tell, Microsoft has learned from the Linux community and decided that having multiple control panels is somehow a good idea.
I have a massive problem with designers who think this complete BS right here is somehow passable in this day and age. It is two thousand freaking fifteen. This should NOT EXIST!

What the hell is the user supposed to do here? Where is the applet they want? How can they tell where the applet they want is? Where's the help system?
It brings up a major problem with the Metro applications: help is almost nonexistant. Sure, press F1, it comes up. How non-obvious is that, and furthermore, what beginner user is going to know how to do that? The answer to that last bit is pretty darned close to no one, ever.

This was a problem when "PC Settings" debuted with Windows 8. Applets were spread across both control panels. At least in that case, the spread made sense (for the most part), so it was nothing more than a nuisance. Here, the spread makes no sense at all, as there's a mix of the two, and what's more, many applets were duplicated, and both do exactly the same thing!
If this doesn't fit the definition of a bug, it really should. It's 2016 now, not 1979. And this is MICROSOFT doing this! Utterly horrible, bad designing, what other stupid decisions have they made under the hood? (more on that last bit later!)

The "Edge" browser, another new feature in Windows 10.

What a freaking joke the whole "new" thing is. You've all been lied to, it's nothing more than Internet Explorer with a new UI, new name, and a slightly improved (maybe, if even that) rendering engine. No extension support either, despite this being the year 2016.
The UI is a complete mess. What in the hell is the point of having the URL bar not near the top of the window, like uh EVERY other browser released in the history of ever? Come on guys, this is seriously stupid.
The whole program is also ridiculously simplified, to the point that if something were to ever go wrong, you can't simply blow away the configuration and start fresh. Quality control? Nope! I can't wait until something comes along and starts trashing the Edge browser and a massive uproar gets started over it. Bookmark my words, it will happen, probably sooner rather than later too.

I'm not using some toy cellphone. Or a dumb tablet. I'm using a computer. Give me a user interface that belongs on a computer, not a tablet or a phone.

If you just must use IE, it is still bundled with Windows 10. Suggesting that, perhaps, the two may well just be one and the same.

What is old is now new again. Fortunately many classic applications are still included in Windows 10.

Shutting down Windows 10. That ridiculously useless "fast boot" feature is still present, but can fortunately be turned off.