The Code School tutorial is prettier and more noob-friendly because it doesn’t require you to install anything on your machine, it has a terminal right in the browser. I also liked the integration between Code School and Github. However, it seems to be “on rails” in the sense that your actions don’t necessarily change the outcome. For example, I tried entering in slightly different commit messages than the ones suggested, and it accepted my commits and advanced me to the next “level”, but when I viewed the commit messages later in the tutorial the commit messages were the ones they suggested, not the slightly different versions I actually input.
On the other hand, the OpenHatch mission required you to download and install Git, which may be less noob-friendly and present a larger barrier to entry, but is more effective at the goal of making people into (minimally) effective contributors to open source projects. By the end of the OpenHatch mission you can be confident that you are able to use the basic functions of git to create patches and send them to upstream projects. I also liked that you had a real git repository on your machine to play with, and your actions had real consequences.