I'm not talking about the store, I'm talking about the operating system itself. Windows 10 has forced automatic updates. Before Windows 10, all software was pretty much equal no matter where you got it from. The problem here is that that's not the case anymore. Software released through Microsoft's own store has access to features other software doesn't, and I suspect the complaints exist because there's no reason for those features to be locked to MS's own store (aside from trying to provide an advantage to the said store).

They will try but are destined to fail miserably.

I don't care too much, already switched to Apple and I'm never going back. Thanks to Valves efforts for other Systems than Windows, you get more games than ever before on Linux and Mac, so I'm good.

They are already failing miserably. It's a shame, Steam can use some competition, but the Windows 10 store is a nightmare.

Tomb Raider is a good example
Steam | Windows10
X | 0 Crossfire Support
X | 0 SLI
X | 0 Windows Mode
X | 0 Vysnc options/Ability to disable
X | 0 Modding
X | 0 Overlay support
X | 0 Mouse Macros
X | 0 Clear Refund Policy

These are standard features, and I'm sure I'm missing many more. With no Mod support for the Windows 10 store, the store will remain dead in the water. The W10 store feels more of a cash grab to justify Xbox One losses atm, and feels half baked. It doesn't stop with Tomb Raider, Gears of War is a mess. With all the Tomb Raider problems and less optimized to boot.

Hopefully things change. I'd love Steam to have healthy competition.

There have been fixes for both. I'm a nvidia guy and I bought the Steam version after I read:

http://www.dsogaming.com/news/rise-of-the-tomb-raider-sli-fix-found-offering-95-sli-scaling-on-two-nvidia-gpus/

I think the game itself has updates since release that fix the issues, but only for the Steam version.

They do not. It's a shame I ended up buying both versions to enjoy the game in 4K. 

I tried Tomb Raider W10 version again yesterday, just to see if maybe things were fixed and nobody has reported on it yet...  Then again no AAA game on W10 store support SLI or Crossfire. This includes Gears of War.

Yup.

RIP Steam. Maybe Half Life 3 will save them in 2096.

I'm waiting for redstone 1 in june, build, E3 and what's the plan for Redstone 2 in spring 2017, before judging... As long as OneCore is not truly out Win10 and all its features are in alpha mode and can't really be judge... But to me this is by far the best Alpha from MS even compared to XP back in the days... If they don't miss the soon to be here next tech revolution, they could turn the table once again like they've done countless of times in the past decades...
Their position allows them to take way more time than most company with way less risks, and way more margin for errors... They have way stronger foundations than most if not all tech companies competing with them (and yes this includes apple, google, amazon etc...)

Those are store features, not OS features. I'm assuming Sweeney is talking about features unrelated to the store. I think I don't have a single problem with store features being exclusive to the store they're associated with (although it would, of course, be nice if similar features could carry between stores in cases where it's possible, e.g. achievements).

Unrelated yet a couple weeks ago I tried to fix my broken wifi on windows 7 desktop by installing and old wifi stick.
However it did not have windows 7 certificates on the CD, so impossible to install. They can easily prevent .exe from running, have been for years for safety reasons.

What I want to know, will I still have full access to AppData?

It's not store features that are the problem here. It's features exclusive to Universal Windows Platform (UWP), and by default UWP applications can't be installed from outside Microsoft's store. (And as for the lack of the features you mentioned, they're practically irrelevant for most applications that aren't games. Also, Microsoft has promised to fix at least V-Sync and I think fullscreen, and is probably looking into fixing the other issues. If Microsoft wants its share of the gaming market on PC, it's going to have to fix them.)

It seems Sweeney doesn't specify the exclusive features. However, the most obvious benefit of UWP seems to be that it's cross-platform (i.e. the same application can work on desktop Windows, tablet Windows, phone Windows, Xbox...), and that can be huge these days. And it's not just that the same code runs on multiple platforms, it's also the fact that UWP has some tools and components that make developing for multiple platforms easier. So basically you don't need to develop the same application again and again for each platform, now you can develop it once to target multiple platforms. Should save a lot in development costs, because software development isn't cheap.

If you're interested to learn more, the following pages seem to have more information:

• https://msdn.microsoft.com/en-us/windows/uwp/get-started/whats-a-uwp (basic info)
• https://msdn.microsoft.com/en-us/windows/uwp/get-started/universal-application-platform-guide (a bit more details, with some illustrations)