After scanning the web, I find myself aligned with the consensus about this show. As such, I’ll leave the deep thoughts to the folks with domain expertise and just post a couple (spoiler-free) comments.
First, the most appealing aspect of non-American cinema is that we can never be confident that things will end well for the protagonists. American films might kill a secondary character, but it rarely ends badly for the headliner. Asian films don’t show such mercy, so the anticipation of potential doom hangs over the entire series. It might not be noticeable for a single feature-length film, however, such uncertainty is almost unbearable when the experience is extended over 11 days (watching only one episode a night).
Second, this show has a moment that is a gorgeous combo of narrative, graphics, and music to create a mid-story climax. The movie Whisper of the Heart and the show Kids on the Slope have similar climatic scenes that absolutely capture the moment with imagery and music. This alone makes it worth your time to watch the first half of Terror in Resonance. Unfortunately, it is no shame to leave Terror after the singular moment (unlike the other two works).
My opinion of the show has only diminished over time. I occasionally revisit the aforementioned moment on youtube, but this show is in the bottom tier of the Shinichiro Watanabe catalog, slightly better than Carole and Tuesday. While the show was good enough that I don’t regret the time, I won’t rewatch it.