That article says that one tower fully stacked is 20 MW, while the Tesla storage is 6 and a half times that. You can somewhat compare pictures between the articles to get a sense of scale.

Seems to me the Tesla system would have a much lower total cost of ownership as its a solid state system (and perhaps even construction costs - getting that much concrete in one place for the tower system would be a large expense). Plus the batteries can respond much faster and more efficiently to changes in electricity needs.