Coming from Windows 7 Pro x64. I upgraded yesterday using the MediaCreationTool. I stopped the download once when it was at 54% and had some problems getting that tool to work again, but it eventually started running again and started downloading from scratch, though.
It didn't take long to install (about 40 min or so). I didn't see any great improvement in how it runs or in bootup speed. It boots to the login screen fast, but the time it takes Windows to completely load, is about the same overall time it takes Windows 7 to boot and load.
It does take some learning to get familiar with getting around the OS. I don't like the added part to the right of the Start menu, but I guess I can live with that. I frown upon the inability to make custom choices of what to select and install for Windows updates. I don't like that! That means Microsoft is controlling what we have on are computer and I strongly suspect there is advanced spyware stuff in Windows 10 because of this!
There are reports that Windows 10 has the ability to disable the use of pirated games and software (primarily Microsoft authored games and software). That's really not a problem for me in itself, but it's an invasion of privacy (to take control of any activity conducted on an individuals PC like that), and that really troubles me.
I'm really interested in Windows 10 because of the new Audio Stack API implementations in the new OS. I'm gonna get around to seeing what kind of low latency improvements are present for WDM and WASAPI drivers. And I got to say I like Cortana (the A.I. from the Halo games), and I want to try out Cortana! :)
There is one important issue I'm having with Windows 10, now. I can't get the thing Activated. I'm getting the following error: Error code: 0xC004C003. I tried phone Activation to no avail. And I've spent a good amount of time waiting on the phone to speak with Microsoft. I also spoke via phone to Microsoft techs and reps. To this point Online and phone activation is not working for me. Microsoft says a number of people are getting this error code, and there's an issue with the Activation Servers at this time. They tell me to give it 48 hours or so and the Online Activation should work. That error code I'm getting has something to do with the server blocking my activation because of the Windows 10 product number I have. That product number on my copy of Windows 10 was automatically given by my use of the Microsoft MediaCreationTool and it's installation of Windows 10 on my PC. I'm not responsible for that Product number. I'll give it a week or so, and if Windows 10 doesn't get activated, I'll call Microsoft, again. Guess this is my price for Windows 10. As the saying goes: Nothing is really free.
Overall, though, it looks like Windows 10 may be a good OS in general and as a host for a DAW.