This CD is available with the imported Playstation version of Dracula X: Nocturne in the Moonlight. I actually won the game in an auction just to get my hands on this promotional CD and the artbook that comes with the game. And while the music CD isn't worth the $50-60 or more you would pay an online store to import the game, if you can buy it cheaper second-hand, this is a rock-solid purchase.
For starters, the CD is chocked full of music. This is no half-hour excursion into the world of Castlevania; at 73 minutes, you get to feast from almost, if not every, Dracula/Castlevania game made at the time of its release, including games that never made it to the states.
Comments on each individual game would require a track-by-track breakdown, so let's just hit some basic points. Konami nicely pays homage to the game that started it all by including all the BGM from the first Castlevania game. It's in stereo, somehow, and sounds a teeny bit more echoey than the original, but you really have to listen for that. The rest of the NES games also have this effect. I assume the Famicom versions of these games had slightly tweaked music over their NES counterparts.
The Game Boy and SNES musics are reproduced perfectly with no odd effect. With the games from other systems like the TG-16, or the Japanese-only games, I'm not sure about how well the sound was recorded in comparison with the originals (since I've never heard them), but the sound quality of the entire CD is excellent throughout.
As for the selection of music, it'd be hard to argue with what is displayed here. Almost all the games have opening music plus the first stage, and some have the ending music. Interspersed from here on are other stage musics, such as "Bloody Tears" from Castlevania II or fan-favorite "Clock Tower" from Castlevania III.
No CD is perfect, though, and there are are two gripes - not even flaws, but just my opinions. First, the repetition of "Vampire Killer" and "Bloody Tears" in several different games could have replaced with other musics from those games - each of these is used at least three times. While they're great themes and each use of them is done differently, it's still the same composition fundamentally. Secondly, I could have done without the music from Dracula-kun and Dracula-kun 2. I can see why they were included - they're genuine Dracula music - but they don't really follow the mood set by the rest of the CD.
Still, these are minor considerations in the face of everything else you get here. The bottom line is, this is a wonderful CD for any fan of Castlevania.