As many reviewers have written before this is a high quality product. Sound and mix are for the most part top notch, only the sound effects during radio transmissions in the first part of "Mountains of madness" are a little too loud in the mix no matter what setup I use (home as well as car stereo) and some high pitched sounds (i.e. the screeching in "Shadow out of time") are really piercing so listeners may want to adjust volume especially when using headphones. The cast does a great job and even though I'm not a native speaker it's easy to follow the stories since every voice is easily distinguishable and spoken clearly. Except maybe some australian or Massachusets hinterlands accents :-)
The folders are made from sturdy cardboard, all the props I've looked at so far are carefully crafted and really increase the immersion. This collection is a strong recommendation for every Lovecraft afficionado who's looking for a different experience other than reading his stories or watching TV / movie adaptations.