Very early impressions:
Windows 10 is awesome. Looks and feels very crisp. Boots, restarts, and runs very fast. (Note: I have it installed on a SSD, and it boots in about 3 seconds, though I've heard it's very fast regardless.)
Setting up Windows 10 was extremely user-friendly and even pleasant, this was one of the [only] things that Windows 8 did really well, and it's good to see they kept it.
All the hilariously overblown outrage over Microsoft collecting your data is incredibly dumb. Right when you set up Windows 10 it explains the data that is collected and why, and allows you to enable/disable every single thing you can send to Microsoft, all the way down to basic error reports. This actually makes Windows 10 the most honest and user-friendly OS I've ever used when it comes to data collection. I turned most of it off, but there are legitimate things to keep on.
The proper desktop and start menu are back! The start menu is excellent, and combines some of the positive aspects of the technology from Windows 8 without forcing it on you as a whole separate screen (though if you're one of the 4 people who liked Windows 8's bizarre split personality, you can choose to have a fullscreen start menu, which is sorfof like Windows 8's start button). The task bar behaves like windows 7, and you can customize it as per usual. It now comes with a built-in search bar right beside the start button that searches both your PC and the internet, which is incredibly handy and one of my favourite features - incredibly utilitarian and modern.
The lock screen, should you choose to use one, by default features a new picture every day, which is a nice little touch, though you can of course make it anything you want. It shows the time, the date, the battery if you're using one, and whether you're connected to wifi. You can customize it if you want to use a password, a pin, or a picture to sign in. You can also customize it by showing info on any program you want right on the lock screen, which is awesome and also incredibly modern.
Unlike many Apple devices there is a proper task manager that Windows users know and love, and like Windows 7 and many handheld devices there is also task viewer (where all the open programs are shown side by side, and are selectable) - in other words, the basic tools that make Windows a powerful OS are back and working well.
I don't know about games yet, but articles I've read have said there are very few compatibility errors, which is impressive considering how new Windows 10 is.
As a bonus, Microsoft Edge, the new internet browser, so far seems quite good. It has an awesome note-taking feature where you can take notes right on a webpage at any time, whether by typing, highlighting, or writing like a pen. You can also take screen clippings at any time and paste them anywhere you want. Very handy browser, but I haven't used it much to give a thorough review. I will likely use it alongside Chrome. I like Microsoft's commitment to privacy so I hope I can avoid untrustworthy Google and switch to Edge, but time will tell if it's superior.
Conclusion:
These are just early impressions, my opinion will change and I'll post my updated thoughts as I use Windows 10 more.
So far it seems like a very utilitarian, user-friendly, SANE mix of all the things that make Windows great, as well as tossing aside the crap from Windows 8 and instead taking the good aspects of it and using them to make Windows 10 better rather than hindered. I have not encountered any bugs at this time.
I like Windows 10 so far, and I especially like how it's free.
