As far as the original topic...
iOS and OSX may have a few new features similar to Windows 8.x, but they are still two separate and very distinct OSes. That alone makes it very difficult for me to consider them "similar" to Windows 8.x.
Also, things always look more polished in a product demo than they are in the real world. We have seen and used Windows 8.x (both good and bad aspects) in the real world, but iOS 9 has not been touched by consumers yet. We'll have to see how it plays out, but IMHO iOS 9 isn't very exciting and Apple is going to have to do a lot more than add split screen to make iOS compete with Windows 8.x or 10 on a productivity level.