I'll preface by saying that I've never seen the original Ultraman TV series and only ever seen a single Ultraman movie at a film festival before watching this series.
Overall I enjoyed the show, the story kept be interested from the first episode and the animation style feels like a unique mix of different kinds of CG. The action sequences were better produced than the drama ones where the animation felt clumsy and unnatural. Although I did like this take on the suits, felt reminiscent of the Guyver animated series.
The audio dubbing in English was not very good, and I just got the feeling that the voice actors didn't make the roles their own, just felt amateurish.
The subtitles in English were also inconsistent with the dubbing. After watching several scenes from the first episodes with both on, I felt the dialogue of the English dub was more idiomatic, so I decided to go with the dubbing instated of the subtitles for this series. In the end I wouldn't recommend this, the dialogue got overly simplistic with little nuance or depth.. but maybe that would have been the case either way.