For me it would be less useful due to the similarity(e.g. I had little to no difficulty learning Spanish as a native English speaker. Sure, there were differences, but the similarities allowed me to focus on and pick up the difference more quickly without being overwhelmed). It would be like going from Java to C#. Some differences, but very few because the base is so similar.
I should have specified it was learning Koine Greek that helped (Latin was somewhat of a bridge that made it less painful, because Latin also relies heavily on declension/conjugation instead of straight word order). Koine Greek is wildly different than English. I think it would be the difference between something like going from an OOP language to something like Prolog.