It's a different card. Mind Spring can't attack, and is, honestly, quite an awful card. I'ld cube numerous fixed size draws spells before it. While you can argue Aeon Chronicler is an expensive Mind Spring, I think its main use case is suspend for X = 1, so you draw a card on your upkeep, and can attack with a fattie with counterspell backup. For it to be succesful, you need an environment where that is a viable line of play, e.g. a format with weak aggro and plenty of cantrips to naturally keep up your hand size.