With iPad Pro, you are still restricted to apps available in the App Store, as opposed to the Mac's ability to install third party apps. The iPad Pro does not have mouse support or a windowed mode for its apps. There are many other power user features that are available on OS X but not on iOS.
Consider your iPad. If it is capable of performing all of the work that you need your computer to do, but you would like more screen real estate, then the iPad Pro might be for you. If you need software that is only available on OS X or would like the traditional desktop experience, you'll probably want to stick with a Macbook.
For me, I would never replace my Macbook with an iPad.
11-18-2015 08:15 AM