I had mixed feelings about this show. One of my favorite characters got horribly mangled during it. How could they do that to Yazan?
Haman felt like a shadow of her Zeta self to me in ZZ. She was too obsessed with Judau, she never let her feelings for Char get in the way to the same extent in ZZ. In the end, she seemed to just give up. I felt like Bright had lost his touch too. What was he thinking, letting a crew of kids run his new ship?
I did like seeing the huge change in Mashimar. I thought they were going to kill him when the show turned serious, but instead they brought him back as a good villain. Judau punching Wong was awesome. On the other hand, I couldn't believe they brought back the MoonMoon colony later in the show. The MoonMoon episodes were just... awful. They deserve to be deleted from Gundam.
My understanding of why the series changed drastically in tone is that Tomino did a rewrite to make it match up with what he was planning for CCA.