Aaaand, I caved and bought the Akumajo Dracula Best Music Collections Box...box. The earlier games, as I've mentioned in other threads, actually have clearer sound (levels boosted during CD mastering process I'm assuming). The tracks on Rondo of Blood even sound better than disc two of the DXC OST. But again, there's that trouble of the scores not being complete—so I intend on just making iTunes/iPod playlists for each game, using all of the tracks from the box, and then filling in the gaps with tracks from all the other CDs. FOR OPTIMAL CASTLEVANIA LISTENING QUALITY.
The box now goes back in the plastic wrapping it came in, likely to never be opened again.