iOS and Android have the apps. Windows and Mac have the full functionality. The only major player who really wants to ties it together is Google, but they want you to be tied to their cloud and targeted advertising. No thanks Google.

The best compromise right now (IMHO) is a Surface 3 and iPad/iPhone. The Surface 3 BTW has an incredible screen very comparable to the Apple "retina" displays, and it's as flat as my iPad 2. A very nice package, pretty close to a perfect portable PC. If I was a Mac user I'd substitute the MacBook Air with retina display for the Surface, but the Surface is better for me and doubles as a tablet. (I'm running Coastal Explorer on it also, and its literally beautiful.)