Amazing yes. But I think that on certain sections they should output the console value instead. I'm specific talking about the Array Spread example as the Babel output in that case is a very roundabout and verbose way of showing me what the Array Spread Operator actually does. I think it would be better to allow the user to play with the operator and see the output of it right next to the code.
Still useful, but yeah, adding the console output would be even better for said sections. Either way, I'm loving this write up. I saved it to run through the entire tutorial, starting tonight.