Macross Series English Dub, Difference between ROBOTECH series?

I recently ordered the new Macross english dub. I absolutely adore the Robotech series, and I'm wondering; what's the difference going to be aside from the fact that Minmay's singing won't be so atrocious now? Supposedly the story follows the original more closely but in what way did the original Robotech series stray from what the Japanese had intended? I've got a lot of questions about this. Anyone who knows, please feel free to clue me in!