I rewatched this one recently and I think it's great!
One of my favorite storylines. I've only got two small gripes which, unfortunately, are pretty distracting:
1. Rodan looks
awful here. After the awesomeness of Rodan '56, the suit used here feels like a huge downgrade. The suit has this goofy bug-eyed look, and the puppet they used for closeups is just terrible. The only times Rodan looks good are long shots (he looks good in the shots where he's carrying Godzilla), but otherwise yuck. Easily the worst part about this movie, which is disappointing because I love Rodan and his role here.
2. The whole idea of the "monster conference" was just a bit TOO goofy for me, considering the rest of the movie. There had to be a better way of handling that, but I suspect goofiness was kind of the point.
Otherwise, I love this one! I have a hard time deciding whether I like this or Monster Zero better, it goes back and forth depending on which movie I saw last! ^_^()