I spent a day at DLP last March. I had been to Paris a few times in the past, so I did not feel too guilty about spending one of my precious vacation days at an American theme park. The tickets were a surprise from my French boyfriend; had he not purchased them I probably would not have gone.
DLP surprised me because it is designed as a truly American theme park, right down to Main Street USA and Frontierland. I thought that there would be greater deference given to French culture, but I was wrong. The cast members are from a variety of European countries, as are most of the guests. That added an interesting international flavor to the park. I visited in March, so the trees were barren and it was cold. That detracted a bit from my overall enjoyment of the park. I did not visit Disney Studios or any of the hotels. I have not yet been to WDW, but I have been to Disneyland in California numerous times and I prefer the California park.
Unless you are a Disney fanatic or have been to Paris numerous times, I recommend skipping DLP. Paris is an amazing city and there is so much to do and see. I love to travel and have been to some wonderful places, but when I am in Paris I know that I am visiting someplace truly special.
Information on both DLP and Tokyo Disneyland can be found at:
http://destinations.disney.go.com/parksandresorts/index?bhcp=1