Even though there's Japanese writing on the cd cases, these releases are actually from the German Membran company. I've heard several sets but not the Dexter and don't own any of them. Sound quality sounds ok for some and not so good for others. Some sound like they've been compressed to death but an interesting and tempting catalogue of titles to be sure. There's usually never any - or very little - accompanying text. There has been a considerable amount of online discussion about how legal/legitimate these discs are and whether or not royalties were being paid. Short story is that they are very inexpensive but probably best serve as introductions to an artist's work. High quality pressings are best found at Mosaic and elsewhere.
Cheers,
Lester