I've played both the 3D N64 versions, the first one wasn't too great, but the second one wasn't that bad. It was basically a remake of the first game but done slightly better. But saying its not bad doesn't mean it was automatically good either
. Neither of them touched the greatness of Symphony of the Night (PSX) and Circle of the Moon(GBA). 3D just doesnt' suit CV games, I think there are some movie demo's of the game on IGN and Gamespot and they look kind of cool but still, using the whip in 3D is too cumbersome.
As a little tidbit, the heroine of the scrapped DC castlevania was used as the heroine for a GBC castlevania game, I think her name was Sonya Belmont. As far as the DC version, I don't think it will ever be released, it was only somewhere around 40% done, I could be wrong on that number.
oh wait.....I just remembered, they did release the music for the DC castlevania I have it on my comp somewhere, it actually wasn't that bad but sounded different from the normal castlevania games.