"Strong story, uneven performance"
There feels like there's some action missing. Laymon's Beast House series is a reasonably well-known, grim and gruesome set of stories, but this introductory story feels like it skips over some crucial parts. Of course, given the unreliable nature of the performance / production, it's not easy to say if this is an actual story criticism, or a result of the production.
The performer's voice work was good, but the pacing of the performance was very rushed, leaving no breathing room to let any suspense or tension build. But much worse than that, obvious editing errors. At a minimum, more than one instance of repeated lines, and there certainly FEELS like there are moments that were left out of this final product even though the story is unabridged. It's hard to tell if this is a result of the production or the story, but the fact that the production has enough known shortcomings to make this a question speaks to the overall lack of quality of the audio itself.
"Outstanding"
If it's not the absolute best, it's certainly a contender.
The story unfolds in an excellent balance. It's reminiscent of a three act play: the beginning act introduces the potential peril of the South Fork Dam and the folly of its construction, Act II sees the dam break and the artificial lake sweep through the valley bringing with it horrific destruction, and Act III--perhaps the most interesting, believe it or not--provides an excellent presentation and examination of the aftermath. This is stunning, engaging history.
Herrmann couldn't possibly be any better.