It's beyond mere Intrusion. It's probably unconstitutional in every nation on earth, but establishing that requires someone take MSFT to court for it.
To see why, well read the license for yourself, and especially the linked Services Agreement.
Since I do legal contracts for a living, I felt it my due diligence duty to show some of the key clauses and explain why they are vile, here. Or, here.
Atop that, are the concerns about for how long security updates will be furnished, because the lifecycle agreement won't cover devices no longer given OEM support, explained here. Or, here. The videos' description has links to the actual MSFT official lifecycle sheet you can read onscreen for yourself, rather than listen to me explain it.
Now, if these license and support terms change to be non-intrusive and actually do support updates, then there are many reasons to adopt Windows 10. The installer is buggy, but it has ever been so, when doing inplace upgrades. MSFT plays well with certain programs pre-installed but not others, same for pre-installed hardware. Why? Well they don't test it on everything, but on selected combinations: so if you happen to have that combination (or near it), then like so many (me included), you will have a smooth installation experience. Else (for so many more), not.
Once installed, Win10 is often compatible with older hardware and software (my stuff is mostly 10 years old or more, and it all works even the DOS stuff via DOSbox). THE TRICK IS TO UNINSTALL EVERYTHING OR DO A CLEAN INSTALL (which with Win10 means 'upgrade' and also 'keep nothing') -- and afterwards, reinstall what you had, often including drivers.
Yet Win10 remains often inexplicably incompatible with video and sound drivers, keyboards and trackpads, programs you'd expect it to work with.. I can't explain why not compatible.
I have noticed one commonality though: if the machine and the parts are commonly used by ENTERPRISE, then the update will tend to be smooth. If instead the parts are customized, or in consumer machines, then typically the update will bomb or be problemmatic. In short, they design the installer around ENTERPRISE standard equipment and software, so the more your stuff is like that (i.e., Dell Latitudes, which is mainstream enterprise level), the more your updating on Windows, will go smoothly.
So my big complaint isn't about Windows itself (although I've many subcomplaints). The BIG complaint is about the unconstitutionality of the License, a topic which the worldwide media suspiciously avoids disclosing.
Edited by brainout, 09 August 2015 - 07:35 PM.