I have a 2014 11" Macbook Air, Acer Aspire Switch 11, Surface 2, Asus X200MA notebook (in addition to a stack of tablets, and an iMac) that I use on a regular basis.
I prefer to keep the devices separate (Windows on the Windows devices, OSX on the Apple devices). For the rare occasion that I need a Windows app on my OSX devices, I use Wineskin Winery to run them. (No need to have Windows installed)
I have iWork 09, LibreOffice 5.0, and MS Office 2011 installed on my iMac, iWork 09 and LibreOffice 5.0 on my MBA, LibreOffice 5.0 on my Acer Aspire and Asus. MS Office comes standard with the Surface 2.
I keep the core workset of documents that I'm currently working on, on DropBox and can edit them from any of the listed devices. With the recent update of LibreOffice to 5.0, document preservation between LibreOffice and MS Office is more reliable than it's ever been.
When I bought my first OSX device, I used both BootCamp and Parallels. BootCamp was clunky as I found myself rebooting more frequently than doing actual work. Parallels worked well except for the constant need to upgrade Parallels (at a cost) every time I updated OSX.