The only thing I can think of that would make the original better than DX is the screen skipping glitch, which allowed you to do a whole bunch of glitches, like having Marin follow you for the rest of the game, or getting to later levels when you shouldn't be able to, etc. Other than that... Oh, the secret ending of the original had Marin with wings, rather than a pic of her that faded into a seagull. But yeah, the DX version is better anyway, imo, so no worries.
"Those whose memories fade seek to
carve them in their hearts...
All dreams are but another reality.
I owned the original and then later on played DX. Adding color to the game just made the experience very awesome. I've beaten the game and knew what was around every corner but I was still excited as ever as if it was something new.
Plus those extra lil additions are nice. The color dungeon specifically for DX is great!
In the dungeons there are owl statues. In the original, all the statues gave you one collective clue towards the completion of the dungeon. The clue was cryptic. In DX, they all give different clues, and the clues are less cryptic.
The only other difference not listed in this thread is the text skip "glitch". In the original, you could completely skip what people were saying by pressing B (I think it was B). Less of a help and more of a harm if you ask me.
Really, DX is better, even if it does have extraneous clue-giving.