Before one goes getting these CD's, I will warn you: it is a very unique format. Even if you have an Emulator II, which is what these were meant for, you'd need either a special kind of CD player known as the CDS3, a piece of hardware long abandoned, or a free software download known as CDS3Tool by ESynthesist. Opting for the latter due to not having an EII, I managed to successfully convert most of the sounds to SoundFont with EMXP, another software download by EMXP, without much of a hassle.
Listening to what I converted, it is clear how popular these samples were, judging from how many records (and even movie soundtracks) used them. They are sampled at 27778 Hz, but that's a somewhat decent sample rate for back then, especially given the only options that had CD-quality sampling at the time was the Fairlight Series III or the very latest Synclavier models.
The samples are organized into various categories and genres, which is pretty impressive for a single collection of third party samples. There are even a few foley effects and other weird noises included, on top of synthetic sounds and acoustic samples.
The wide diversity of sounds, especially for unusual ones, may be why it was so heavily used by Alan Howarth in the Halloween 4 and 5 soundtracks. Other more famous users of these CD's would be Peter Gabriel (the famous Shakuhachi sample from "Sledgehammer" originated from volume 1), Enya, Depeche Mode, and even Gary Numan, who was normally reserved for the PPG Waveterm.
Interestingly, Peter Gabriel probably noticed one of the samples in the Dark Moods multisample had sampled from his soundtrack "Quiet and Alone" (from the movie Birdy), as well as the drums for the original version of "I Have the Touch". There are a few other forms of preexisting work sampled from, though mostly limited to classical music (the orchestral hits and stabs).
Unfortunately, due to the limited demand for the CDS3 players, combined with the Emulator II long being discontinued, these two volumes are fairly hard to find. Even their current distributor, Q-Up-Arts, seems to have a limited supply. Nonetheless, if you do manage to find these CD's, I highly recommend them if you have a sense of nostalgia for mid-to-late '80s music!