I'm fine using XP, Win 7 and Win 10. I like them all. I'll stop with XP until the machine dies (it's like an old and trusted friend) Win 7 just works, I have had very few issues with it. And Win 10..well it's an adventure and I like what I see.
"Why some people agree with using W10 on a privacy forum" People have different priorities. For example: I use 99.999% of GPL software, because I think this kind of freedom needs to exist everywhere. However, there are certain packages which don't have good GPL alternatives so I need to use the proprietary one, like the FGLRX driver. It's not Free, but it works and hits the stop that I want it to hit (a working OpenCL implementation, which doesn't exist in the FOSS driver). I opened one exception of "freedom of free time" before the "freedom to read the source code" just in this particular case, because I don't have the time to tinker with this anymore and compile 2 or 3 Kernels every week just to test if the driver is working. In addition, my processor goes to 75ºC when rendering via CPU, and with the proprietary driver I can render with the GPU + have 50% performance gain (which means more free time) and the GPU only goes to 40 to 45 ºC. I think the same apply to Windows users. While 7 is way less invasive, it may not work as the person needs, specially if you consider the update problem (which seems to be resolved but I don't really know). Also, there are numerous tools to tune down the spying and probably make W10 less invasiv than 7. Obviously Microsoft may decide to counter these measures, but then again the community will play this "cat - mouse" game and avoid the spying once more. The world is not white and black for everything, people.
I thought I would too, hate OS X. But when I can get a New 27" Custom Made Mac for Less than Half Price legally, I couldn't pass the deal up. Now I could enjoy both Worlds, OS X and Windows 7 on the desktop. I'm still thinking of changing our laptop to Linux for a test run.
I thought the opposite, and believed OS X would be better than Windows, until I got the opportunity to use it about 5 or 6 years. However, I hated it then and still do now. I'm not saying that OS X is bad OS, it's just my own personal opinion.
XP is awesome for it's minimal hardware requirements. When I was using XP and Vista dual-boot a few years back, I found myself using Vista more. When 7 came out, I no longer looked back.
I use Windows 7 on my desktop computer, Windows 10 on my netbook (rarely use it, mainly for testing) and Windows 8.1 on my work laptop. Personally I like 7 - it has everything I need and it is stable. Windows 8.1 is OK also, I only add Classic Shell start menu for convenience. Windows 10 OTOH I use mainly for testing and staying familiar with latest OS (to support customers). I don't like some changes that came with it and it also didn't provide anything new I would be interested in. For now I won't be using it for my real computing.
It just seems to be very lmited and really badly designed compared to Windows. I don't like the dock, as in my opinion it takes up too much screen space. I prefer the task bar in Windows as it occupies the whole width of the screen and is not as tall. If you resize the dock so it it is not as high, it also becomes narrower. It seems illogical that menus are at the top of the screen and not the top of the windows. I don't like how clicking on the close button on an app hides the window but leaves the app still running. I don't like the lack of a Start Menu, and that most of your apps sit on the dock, as it is way to cluttered in my opinion. You can use iTaskBar to get a Windows still Task Bar and Start Menu, and it does the job well. But of course, I don't need any extra software to get them if I stick to Windows.
My Vaio S brightness control and some other functions not working properly in Windows 10 so Windows 7 is a suitable choice right now.
Most likely it needs a different video driver. I've upgraded two Vaios to Windows 10 and had no issues.
Mostly still using 7 on the everyday PC, but gradually getting used to 10 which came with the new laptop.
My pet peeve was how it didn't automatically arrange files in Finder. Delete or move something, and by default it will leave the white space.
Still running a hardened XP SP3 with the POSready/WEPOS registry tweak. Have had no problems since it's EOL just as was the case before it.
I can't vote for more than one BUT I have Windows 7 on 4 computers and Windows 10 on one computer. Happy with all of them.
Windows 10 now v.1607, after some effort and a lot of trial and error, runs on my little work station pretty much as MS hyped it would. But it took a bit to get there.
Windows 10 LTSB. I also have a MacBook Pro with OS X. Both computers pretty much get equal attention.