Over at MacWorld, Jason Snell has written about how his MacBook has become secondary to his iPad:
For the past year I’ve been traveling with a 12.9-inch iPad Pro and leaving my MacBook Air home whenever possible. Traveling with only an iPad can feel freeing and it can also feel confining, depending on what you need to accomplish. This week I took a trip and brought my laptop along like the old days, and was reminded about what the iPad does well and where the Mac still has the upper hand. - MacWorld
This is the closest opinion piece about iPad/Mac that matches mine. I also love my iPad (I have an Air 2), but there are some things that it just can't do. Like hacking around in the Terminal, manage files better, and also programming - It's possible on iOS, but it's massively better on the Mac.
My Mac will always come first, but in the scenario of travelling, my iPad usually comes out on top. Because it's mostly work that makes me use my Mac.