We did the same thing last month - stayed in Paris and took a day trip to DLP. We've been to
Disneyland and DisneyWorld many times so we concentrated on things that are uniqe to DLP.
-At the MK Phantom Manor is great; it's very different so don't miss it.
-The dragon in the dungeon under the castle is impressive; we went through the entrance in Merlin's(?) shop.
-Pirates of the Caribbean has many of the same screnes, but in a completely different order.
-Alice's Labyrinth is unique to DLP. Take time to wander through it.
-It's a Small World is similar, but a lot more dolls.
-Main St stores - be sure to look up at the ceilings for all of the details and decoration. Also, the covered arcades behind the stores.
-No Mr Toad ride, but if you're a fan, Toad Hall Restaurant has lots of fun decor.
-At the Studio the entryway is unique, again a covered walkway.
-We walked through the new Toy Story Playland, but lines were very long for all of the rides.
-CineMaagique was a clever montage of films and a chance to get off our feet.
-Wanted to see Remy so we had an ADR for lunch at Restaurant des Stars and were seated immediately. Plenty of interaction with Remy.
In General:
-A lot of attractions and CS restaurants close early so plan accordingly. Park hours were 10AM to 10PM the day we were there, but a lot of things closed around 6 at the MK. Studio closed at 6 also.
-Wear comfortable shoes - lots of cobblestone walkways and uneven pavement.
-They were starting to decorate for Halloween in the MK when we were there.
-DLP is visually far more detailed. Take time to look at the facades, interiors and landscaping.
-We took the train from Paris and arrived a little before opening. Although everything was automated at CDG Etoile station, it was all clearly marked so it was relatively easy to buy tickets and find the right platform.
Have fun!