Thing is, i've never considered the OS to be a massive factor - as odd as that sounds, being in the Mac world for so many years i'd see that yearly excitement for the next OS... And i'd never understand it - Myself, i just work - if i open up Cubase, or any other app, it doesn't matter if it's MacOS, Linux, WinXP, 7, 8 or 10 - i'm only focused on the app itself, outside of the walls of that app just dissapear.
I've never had to deal with a machine crashing and instabilities since way back in the XP/2000 days. I think as a matured user you just learn how to maintain a solid OS no matter what so perhaps i generally have a smooth ride of things by sticking to the basics.
Also, i find it very important to check my setup and ensure that all my backup/restore plans are in place - so i do a clean install/restores etc. every 3-4 years regardless. It's the only true way of knowing and keeping your backup plans 'real world' effective. Again. That's just me.
It doesn't matter what level you are though, if you want access to online sharing, backups, or sample libraries on demand then you have to be connected, and to be connected you need to be secure in the host OS.There's nothing about it that would hold me back from doing whatever I want for the foreseeable future. This is just my own amateur music room, it's not a commercial studio or similar facility.
Of course, this may not apply to you, but i mainly create straight up guitar based music - but then i do have plugins such as loopcloud where i can lookup sample libraries and try them 'in-place' within my DAW if i want something a bit different, the same with some synths i use and Native Instrument plugins/libraries for orchestral parts. I really like having an online library that i can pick and choose from rather than paying/downloading for 100's GBs to sit needlessly on my drives.
I would've said exactly the same years ago with older OS's, but with Win 10 it's truly been the best yet. Just because Win 7 works well for you doesn't mean that Win 10 wouldn't. And hey, i thought Win 10 would be hell before using it - i was dead set against it and the only reason i tried it for audio was purely down to finances. I was looking at replacing 2x Mac Pros Xeons (2012) - and the new Mac Pro pricing was announced so i picked up a cheap i7 Win 10 machine from ebay for 250 quid as a tester and it's been fantastic.In fact, it's given me one of the most stable setups (of any type or for any purpose) I've ever had.
I had a Win 7 machine, and it's just so much better than that - but i can't really compare apples to apples due to the CPU's being quite different and SSD in the Win 10.