Ok, I read a bit about vagrant and the ionic-box (here for example: http://digitaldrummerj.me/ionicbox-notes/).
What I didn't know until just now, is that this box is shell only and there is no GUI involved. And I develop on my machine, not in a VirtualBox.
Now I get why this could be interesting! Consistent environment, always the right Ionic CLI or Cordova CLI version I used the last time. It even doesn't matter if I am on Mac or Windows, as the vagrant box is always linux and behaving consistently. That I can wrap my head around, that sounds awesome.
That I still have to go "outside" to build on iOS is a bummer, though. I have to investigate if there is a better way for that... Maybe just open the xcode project from the "shared" folder or something?
But @bengtler, does this help to solve my "I want to be able to see (read: diff) the changes I get by updating my plugins or recreating the platforms?