I prefer Ayama Kojima's artwork. Her artwork makes Castlevania special.
Though the old school anime art in Rondo has it's own charm, I wouldn't say go back and change it.
I've been waiting for the day they'd do a Dracula X Rondo of Blood port.
Including the original and SOTN is very generous. Though the only awesome extra for Saturn was Maria as a playable character. She has triple jump and neat magic spells.

Otherwise the Saturn has terrible load times, more slow down and the transparent effects looked grid-y. Just ugly. The extra two area's were lackluster and small. The Cursed Dungeon I hated it, just bridged two areas together and had some of the most annoying enemies. The Garden was cool but small with a little purple armor guy as the boss, really much too easy. But it was worth playing thru once as Maria.
How ya doing, buddy?