OSX since 10.4 has had this nice feeling of all the apps doing all the basics well and integrated together, and since 1990 with Windows Microsoft's GUI was always well behind the standard set by Apple.
I was one of the few over the moon when Apple went Intel, and bootcamp was great however it just still showed how far they were still behind with XP. Vista was two steps forward one back, had terrible performance issues, bugs and glitches but under the hood it showed a lot of potential. Mac users of OSX 10.1-2 that might sound familiar.
Windows 7 however changed the game though, it's the first and still the only Microsoft OS comparable to OSX. I have had none of the stability problems on Windows 7 on any of my systems, but I don't install adware, crapware, toolbars, search hijackers and keep all my plug ins up to date vigilantly.
I can understand any Win 8 users relieved to be using OSX, though I support it I wouldn't dream of using it myself aside from on the test rig I have. 7 really didn't need replacing as like Vista lots of 8 was not very well thought out with the metro stupidity, confusing a desktop OS with a tablet and menus options spread stupidly all over the shop, though like Vista underneath there was much to find good in. 8.1 was an improvement, half way but still not enough. From what I hear it will be 8.2 that will give a desktop OS back that succeeds 7 as a worthy competitor, though in my case I feels it's more complimentary to a Mac.
They both do different things good and have their own strengths and weaknesses and I couldn't do without either of them!