From a quick scan of this CO / USA discussion thread, I took away one interesting observation:

It seems that if you are fluent in the increasingly obscure language which used to be the world's "lingua franca" and/or you have lived in France and therefore have been initiated into the various rites and rituals of acceptable French business and social interaction, CDG can be survivable and even ok, especially if you have a sense of adventure and have had 200 trips in which to finally figure it all out. Otherwise, you are likely to be in for a tough, uncompetitive, consumer-unfriendly experience.