Please note that tomorrow, road traffic is likely to be quite a mess in and around Paris, as farmers are staging a protest against perceived government inaction for their troubles -- they plan on bringing 1,000 tractors to town and blocking the autoroutes into town. then they will converge on the east of Paris, to Place de la Nation (a few are supposed to go to the National Assembly).
All this is to say - if you're arriving at CDG or Orly tomorrow, I would prefer the RER to a taxi or anything traveling via road!
EDIT THURSDAY MORNING: The group that had filed to slow down rail traffic announced last night that they are lifting their request -- i.e. they will NOT be blocking rail traffic. (They've also threatened to hamper rail traffic, but I don't know what the effect of that will be. Will keep an eye on the news tomorrow morning and report as developments warrant.)