I am curious to hear your comment about Windows 10. I have been using it now for some of the Windows-only software and also for Windows software deployment and i don't really understand what the fuss is all about. Sure, its not as disorganised as Windows 8, but the search still does not work, the windows Explorer is abysmal for file management, and the stock support for different file formats is still pretty much non-existent despite improvements. They made a virtual desktop UI (finally), which is a complete joke because it lacks basic functionality like dragging windows between desktops. The entire system is still a dysfunctional mix and match between different UI styles (some system dialogs remaining essentially unchanged from Windows 95) and other stuff blatantly from OS X and KDE. I understand that for a Windows XP user, this seems like an improvement. But for a OS X user, who has had all these features (with much better functionality BTW), this surely must look like a sad joke.
Example of the dysfunctionality: if I go to the start menu and go tot he settings/network and internet, I have the option to look at the different connections. Not only is this menu organised in the least space-efficient manner possible (Ethernet connected, really, is that all you have to tell me?), but there are also other system dialogs that offer very similar functionality (networks and sharing center, anyone?), but are organised completely differently. Not only that, but some dialogs are not even accessible from the settings panel, like the above mentioned networks and sharing center. For instance, if i want to know the IP of my computer via the UI, I have a number of very different options which all involve sequences of clicks through a confusing number of buttons. In contrast, in OS X, I either go to Settings/Network (where it would automatically select the active connection for me), where the IP is conveniently written, or I simply option-click the menu bar icon to get all kinds of diagnostic information.
For me, the above illustrates the insurmountable gap between OS X and Windows: its about quality, attention to detail, and the will to do a proper job. Apple developers actually care about their system, and they try to make things logically consistent. Yes, they fail sometimes, the quality control of the software is not the best and the choices they make often annoy the hell out of us users. But Apple is following its vision and it is passionate about it. In contrast, Microsoft seems to aimlessly drop random stuff around, with little regard to coherency or artistic sense. I fail to see any significant difference between Windows 7 and Windows 10 and so far, I haven't obsessed a single feature in the new Windows that would make me even think about possibility to switching from OS X. Of course, your mileage might vary, but at least for me, there is not a single thing that Windows does better. It tries to emulate some of the things from OS X, but at least in my experience, the copy does not come any close to the original.