I just finished watching Macross for the first time. Compared to Robotech it had a little more violence, some mild language, a tiny bit of nudity, and some extra scenes. Also the characters are fleshed out a little differently.
Anyone who cries that Robotech is some ridiculously edited piece of trash is wrong. I preferred Macross to Robotech, but actually preferred the Robotech music in some spots (but the Minmei songs were better in Macross).
The biggest change was the story was tweaked a little for Robotech to bring in the other two series. Some dialogue Robotech used I thought was actually a little better in a few scenes.
I'll probably pick up the box set for Evangelion with my next check.