Re: Things MS got right?
Windows 10 is in a statistical dead heat with Windows 8.1, as per Giordon Mah Ung [PCWorld, 10 days ago, using build 10240 - the GA build]
Windows 8.1 was AT MOST 6% faster than Windows 7, on the same hardware. This is only perceptible if you have had previous disposition to it, or you carry a stopwatch every time you use a computer, and have it one hand while typing with the other. [not certain of when but shown by Adrian Kingsley-Hughes, ZDNet, quite a while ago, though you should be able to search on it with those cues]
No matter what the fanboys say, there is only one place where Windows since version 7, is truly faster - initial setup, which hopefully you don't do too often.
Whether anything has improved since Windows 7 is a decision you must make for yourself, because there are a couple of things better, but so many things worse [and terribly irksome if you have used Windows for more than a month of your life].
Windows 10 seems to be truly pleasing only those people who wish to be fanboys, and their liking it is seen as some badge of honor, no matter how bad it really is. Though one might be pro-Windows 10, if not blind, it is clear there is at least another 2 years work needed to get it to where the inconsistencies and errors are at a low level, so as to not be a constant source of irritation.