Windows 10 Telemetry (a personal testimony)
First off I want to explain my level of expertise, none of what I know is certified and solely learned the hard way by being first a PC gamer and now rendering since the late 90's. Tired of paying for replacements or repairs early on I realized that I needed to be able to support my PC habit or quit. So I learned how to build, repair, and maintain my own systems and networks on my own the hard way with many mistakes along the way and have seen nearly everything break in a pc at one point or another. I admit I am mostly a hardware guy and know software enough to get the things done I need to and can do journeyman software repair (malware removal, registry repair etc). PLus I have over fifteen years tech support experience in an unrelated industry which is only important to illustrate I have alot of experience with troubleshooting.
Do take what I say with however many grains of salt you wish.
I have a modestly decent system for CG rendering, here are my specs:
Gigabyte socket 2011 motherboard
Xeon E5-2620 v2 CPU
EVGA gold 1050 PSU
32 gigs of DDR3 1600
GTX 980 ti
GTX 970
I have been having a great experience and am an early adopter of Windows 10 with the above system. During installation I turned off all the tracking stuff and all the advertising and privacy stuff, and it has stayed off for my btw even after the many updates since the upgrade.
Overall experiance with this OS has been very positive first off, the task switcher allows you to open as many virtual desktops as you wish, you can easily close tasks with it (no more ctrl, alt, del to get to the task manager). Plus there was a noticeable performance improvement (I just recently added the second card AFTER the Nvidia mulit card glitch was fixed) in render times, around 20 %.
Here are the things I feel are issues:
Updates need to be more informative, they are not telling you whats in them and that is something they need to correct if they are going to not allow you to manually update.
Edge browser needs extensions badly, but Microsoft has said they are coming next year, still I dont use it because no ad blocker.
Now as for the main reason for this post is because I finally had a BLUE screen not long ago. There was a picture of a sad face and the message said Windows was sending info back to Microsoft then the message changed to say that Microsoft was repairing my registry, along with a counter from 0 to 100%, when it got to 100 it rebooted. It rebooted no problem and I went to Microsoft to ask someone about what happened, about them collecting the info and the repair.
They told me that this is what the telemetry is supposed to do, to help you in crashes like I experienced, and that no personal information was collected. I also do not use my Microsoft universal account to log in, I still use the same logon I used for Windows 7 so that along with turning everything off during installation protects my identity from them.
So for those concerned about privacy with Windows 10, here are the steps:
During the upgrade use the 'Custom Install' in small blue letters over to the left of the BIG 'Express Install' button they want you to press. Then TURN EVERYTHING OFF that you see including the Edge Browser as default unless you want to keep it as default but if you turn the default setting off your current browser will remain default (Firefox for me), anything you want on you can go back to turn on later if you want. Do not tie it to your Microsoft account either, and you should log on just as you did with Windows 7 if that is what you had, if you are on Windows 8 or 8.1 and do not use a local account to logon (in other words you logon with the Microsft account) then this probably won't work as it will find the master account and log into it for you.
For Windows 7 users who upgrade this way and do not tie into the Microsoft account, the con to this setup is you will not be able to use the Store or the Movies and TV apps or other services without tieing in to your Microsoft account first and therefore you will not be able to use the Univeral Apps either, just so you know. There is a trade off to doing it this way, but it's just like Windws seven was before just now its Windows 10.
If you decide to take the leap, Nvidia has released many driver updates already, the multi card issue is fixed, and the other bugs and missing drivers are getting worked out already. The first big update is coming next month already too.

Comments
As long as the updates are mandatory and -- worst of all -- codified in the license agreement, Windows 10 will be at best a secondary OS for gaming purposes. No self respecting professional should support this nonsense.
I was excited to upgrade from Windows 7 to Windows 10, and did so on the day of its release. I also did everything you suggest here; not linking to a Microsoft account, not using Cortana or Edge, disabling as many of the information sharing options as possible. I even researched ways to remove Cortana, the Store, and other Microsoft features that I didn't need. About two weeks later, I got hit with a gigantic Windows update that undid almost all of that.
Last week I bought a new SSD drive and put Windows 7 back in. Oh how nice it is to once again have borders on windows, gradients on windows, a Start menu that can actually be customized by the user, and not have to sacrifice privacry to access what should be basic features.
Windows 10 is not terrible, but it's no Windows 7.
It'll be Windows7 for me until they hit 128 bits - only reason I will change.
- Greg
None of my default settings have ever been changed and I just updated right now, I am not saying what happened to you is untrue, just saying it has never happend to me once. As for Cortana and the store, they are irrelevant and take minimal space, so I have just unpinned them so they are not in my way at all and I never turned them on in the first place so not a concern.
One thing about Windows 10 that really irritated me was the removal of Windows Media Center though, I am not happy about that.
Sorry for the offense to everyone, just trying to share my experience.
As I said, take what I say with a grain of salt. I will let this thread die now.
Oh my default settings weren't changed, but all of the work I did to try and keep Cortana, the Store, and other stuff from running was reverted. You don't have to apologize, I'm glad to hear that Windows 10 is working for you. Like I said, it wasn't terrible for me, but I found there were a lot of things about 7 that I preferred.
For me personally, Windows 10 is a privacy and an update nightmare. Windows 7 is not 100% perfect there either, especially since more and more "call home" features get installed there as well (or at least MS tries). The whole licensing route they are likely taking does not get my approval either - their EULA is prepared for changes there. At the moment I stick to Windows 7.
I rid my system of Cortana by renaming the directory Cortana resides in as explained by some savvy people, no more Cortana service loaded on my PC. And that still does not help with some of the other stuff that gets sent to Microsoft, even when you have it, supposedly, turned off via the settings.
Looks like we will have to keep hoping that we keep getting more and more tips to defeat these privacy intruding features Microsoft has shoved down our throats.