Fist time playing it..
The most notable difference should be the graphics, the sound is different too. Other than that the game is the same, so you won't miss anything going one way or another, maybe you can try both and see which one you find most appealing.
Even though it's simpler looking, I like the original version the most because it reminds me of the Commodore 64 version, but I plan to play the enhanced version next time.
Have fun! :)
Oh, make sure to keep several saved games and save often. Unlike other LucasArts adventure games that followed, there are a few things you can do here that can get you stuck unable to solve the game. So it's good to have some previous saves to go back to, just in case.