The first season was awesome. It had great animation, interesting characters, and a decent story direction. The first episode alone was forgetin' crazy, but comprehensible. It was almost like a movie condensed to 25 minutes, but not in a bad way. Mechanical design was solid, they weren't god-mechs and the focus actually wasn't on them.
R2 was loving bad. Good characters were killed by bad characters (who shouldn't have existed) that died anyway, focus was put into unimportant side characters, and because of all the bullstuff the story direction was all over the place. The first episode of R2 was a massive excuse to plug Kallen fanservice. The absolute ending was the only good part, and even then it wasn't done as well as it could have been...like the entire second season.