I am still on Yosemite with Office 2011. Over the past year Office 2011 has been less and less stable, getting worse with each update (seemingly) to either Office or the OS. In particular, slide show mode in PowerPoint crashes fairly often. I often give full-day seminars and can now expect 4-5 crashes in PowerPoint each day.
Last year they started trying to sell Office 365 for the Mac, which was pretty comical given that they hadn't updated the product apart from security fixes in over 3 years. Now that 2016 is out, I am faced with the question of whether to purchase a single license or get the subscription. If any other office-type software could actually produce and consume MS Office format files for interchange with everybody else in the world, I would use it. But I have tried OpenOffice and I have tried the iWork suite, and both are basically crap. Office, being the de facto standard, is an evil I have to live with.