I got my first Mac about 15 years ago when I inherited a neighbor's used Quadra. It was a dinosaur even then but I found myself liking it. When Mac mini came out I snapped one up on the first day. I was still using Windows as my main desktop OS but I've been using Linux as my server OS since 1998. In 2008, I moved my desktop to OSX and that started the rapid slide of my entire household over to OSX.
Meanwhile I still use Win 7 at work and it is PAINFUL. On my MBP, I have the factory 7200 rpm disk. On my newer Windows box at work I have an SSD. And my Mac is STILL faster. I've watched SSD prices slowly decline to the point I find them to now be "affordable" and in a few months I might buy one for my MBP but I'm in no hurry as OSX works so well even without an SSD.
Would I go back? Not based on what I know today but I must admit Apple is making some glaring mistakes in the evolution of OSX. I have had to abandon mail.app completely and I'm now using Airmail. I hope Apple wakes up and brings back basic reliable functionality to mail.app because it makes them look a bit like Microsoft with its total failure to retain capabilities that were there before Mountain Lion and Mavericks and introduce new capabilities that actually make life better. The only improvement from Snow Leopard to Mavericks is moving memos out of mail.app to its own app. Everything else about mail.app simply blows chunks. While this is not enough to push me back toward the mess that is Windows, the idea of going back is not entirely anathema. It depends on what my day to day needs are and these days I need OSX.
I've already demonstrated my willingness to exit the Apple ecosystem for capabilities that are essential to me. I replaced my AEBS with an ASUS AC1750 class router (rated #1 on smallnetbuilder), I buy my music and books from Amazon (so I can read or listen cross-platform), I already mentioned dumping mail.app for airmail above, rather than leave my internet and email presence at the mercy of Apple (me.com) and Google (gmail) I've even set up an outlook.com email "just in case." It's more important to get the best than to be blindly devoted to a particular company no matter how much I might like Apple in general.
Somewhat unlikely reasons I might go back to Windows:
Further removal of essential capabilities from OSX and bundled applications (trying to make it too much like iOS).

If I ever needed to run a Windows app non-virtualized (due to licensing).
Current reasons I would never go back to Windows:
Much less time spent fixing problems on OSX versus Windows. This is KEY.
Virus software and updates.

This is a close second.
The way MS handles updates vs the way Apple handles updates.

The way MS enforces various DRM methods including long laborious serial number entry and software activation and re-activation in case of a hard drive crash.

OSX automatic app updates.

Photostream and other aspects of iCloud that make my life simpler.

Mac build quality. Lenovo is nice but Apple gear is still a lot nicer.
So while it's not impossible for me to go back, it's not very likely.