Hi, we just came back, I will put in my 2 cents. Since you are in Paris for only a few days, I think you are better off making paris your home base, rather than DLP. I would suggest the Opera area (where we stayed for 11 days) because you can take the RER A into DLP for a one day
Disneyland fix, then buy a 2 day pass on the L'open tour with hop on/off privileges (they run from 9:30 until 6 pm everyday), and then there are 4 metro stations nearby within 2-3 blocks radius so you can get a connecting train to take the RER C to Versailles.
1) Get to Versailles before 9:30 am (mob starts around 9:30 to 10:00 am. We got there on Friday 10:00 am and there were many tour groups in French, German, Russian, Taiwanese & Japanese.
2) The L'Open tour's Grand Tour starts from Rue Auber (get on the first bus and you can all sit on the top of the open double decker) we got tons of fantastic pictures. Otherwise it would not be possible to take pictures of large structures with your self in it (Eiffel Tower, Arc, Notre Dame, and etc.) Don't have to be paranoid about pickpockets and these buses run very often. We stayed at a hotel only 1 1/2 blocks away from the Rue Auber L'Open tour main office and RER A station.
3) More eating options (price wise and diversity wise) if you stay in Paris
4) You can save more money and time by staying in Paris rather than DLP. I think the theme parks are pretty doable in one to two days.
5) You are going during the summer months, expect mobs at DLP and the subways.
Hope this helps. Wish I could be an ant in your luggage.
Cynthia