There's parts that look decent enough.
My biggest problem with the CG is the robots. The entire show runs at a good fps the whole time, but when the robots show up they look like they're animated at 15 fps. It clashes really hard. Eventually I got past it, but it was still pretty jarring. Some of the effects and designs were pretty interesting if I remember correctly. I feel like a lot of the story was missing from the show. I didn't read the manga, but the story of the show seemed pretty barebones and more focused on the bigger events.
Granted, the last time I watched it was a few years ago so I could be remembering wrongly, and I have no idea if the 2nd season ever came out. If it did, hopefully it was a bit better, and funded better.