"- Better GUI integration"

I don't know what this means. GUI integration with what?

"- Standardized and complete API going beyond simple libc and POSIX (which are quite long in the tooth now)"

Gnome provides a quite impressive and modern GUI API, and so does KDE. SQLite has a great database API. MySQL has a great database API. OpenGL is a great 3D API (admittedly lagging behind DirectX, since few games target OpenGL to push it forward). SDL is a solid media API. There are great APIs for big math, low-level system constructs (Boost, for instance), disk and data, media of many types, etc. There's a library for everything in a Linux system, probably three or four of them. Just because they are not from one vendor does not mean they don't exist, or that they aren't good.

To insist that Linux and Open Source operating systems play by the same rules as Microsoft is to stack the deck in favor of Microsoft and Windows. Luckily, Open Source can opt out of that system, and build awesome things without needing a central commander to determine what is and isn't available. Saying that libc and POSIX are the only standardized APIs on Linux is like limiting yourself to only using applications from Microsoft; thus removing nearly all of the reasons to choose Windows. I have conceded that Windows has vastly superior application support...unless you're willing to say that Windows only has a couple dozen applications, because no others come from Microsoft, you can't ask me to give Windows the nod on libraries because they don't all have a POSIX or standards body approval on them (Microsoft doesn't get outside standards approval for most of their APIs either, while we're on the subject). A modern Linux system has vastly broader and deeper API and library support in almost every area. You may prefer Windows APIs, which is fine, but a lot of folks prefer the Linux options, and there's definitely a lot more variety in the Linux world.

Linux also has way more awesome and plentiful mobile APIs than Windows. Windows isn't even a contender in this space.

"- Access control lists"

Nope.

"- Nicer driver system and better driver support"

I disagree with the "nicer driver system" assertion, but even when we just take it to mean "better support for the most modern hardware", ReactOS doesn't replicate it, anyway. Driver support in ReactOS is vastly worse than driver support in any modern Linux distribution, which is mentioned in the article, where it discusses running ReactOS on virtual hardware, and the problems that come when running it on real hardware. ReactOS is also currently trying to replicate Windows XP. Drivers are no longer coming out for XP for the most modern gear, and new drivers don't work with XP, so even when they reach perfection in ReactOS and it can load all XP drivers flawlessly, they will still have much worse driver support than Linux.

I'll also mention that I lately have more problems with drivers on Windows than I do on Linux. I have a handful of older USB and Firewire devices that simply won't work with the latest version of Windows because the manufacturer isn't making new drivers, but continue to work fine on modern Linux versions. From my current perspective, Linux has much better hardware driver support...though if I were buying new hardware, I might have to check the web to be sure there's a decent driver for the hardware I want to buy.

But, this is all just a bunch of random Windows/Linux fanboy ranting about random ancillary stuff.

UNIX is a superior design at its core. The simple beauty of it is a thing of wonder. Windows, and its creaking DOS underpinnings (C:\, really? we still have C:\?), is a horrorshow by contrast. I made my assertion above based on the belief that anyone who understands both systems couldn't possibly come to the conclusion that Windows is the better OS. It may have more and better applications (it definitely does). It may have more and better drivers (debatable at this point). It may even have a few features that are better than the Linux equivalent (definitely, and the reverse is also true).

But, the Windows OS...the soul of the thing, particularly from the perspective of a software developer, is so obviously inferior to Linux or UNIX that I have a hard time even comprehending an argument to the contrary. This is a limitation on my part, I guess. I just can't comprehend a mind that thinks so differently from my own.