I don't know, "worth the extra money" is such a subjective area. If you can afford it, go for it. As someone (possibly here) once said, when you buy quality, it only hurts your pocketbook once" (paraphrasing).
I have the Turbo S, and DID upgrade the crossovers, because even though I love the Turbo S' soundstaging, slam, liveness, etc., the poor quality crossover parts covered up a lot of what they are capable of. Good luck!