I often hear or read people referring to iPads as toys. I don't agree.
I use my iPad Pro as a "productivity device." Multiple SSH terminals open at the same time to my servers, the publishing system I now use to write my books, cloud based note taking and research (using Google Keep, Evernote, Word and Notes, etc). I also read eBooks, listen to audio books, and my wife and I use it to watch Hulu TV, Netflicks, HBO Go, and purchased Google Play movies and TV shows.
I find the iPad an awesomely useful device. I only use my laptops for software development and since I use Emacs for Lisp, Haskell, and Ruby, with multiple SSH terms that I can flip between quickly, the device also supports programming.
I do spend a fair amount of time in IDEs like RubyMine and IntelliJ on one of my 4 laptops, but I just prefer mobile devices whenever I can use them. In addition to my iPad Pro, I also get a lot of use out of my iPad mini 4 and Android Note 4 phone. The trick is having all of my data available on all devices and realizing that most value of a knowledge worker (software developer in my case) comes from thinking to understand problems rather than typing on a keyboard.