Hadn't thought of doing that - I'm not a natural Linux person myself and I'm repurposing it for an 11yo. But maybe it's not so different from their school Chromebook for what they need. Just removes some of the nice Apple family features and the apps they'd be inheriting, but that's what I get for not paying the tax with new hardware purchases.

11 is a great age to start learning Unix.

Edit: I know Mac OS X is a Unix and Linux is technically a clone, however, of the two, Linux & GNU is a much better environment to learn in.