Chances are you will be ready to head into Paris earlier barring a delay in landing. Regardless, I think the RER is a terrific way to get into Paris from CDG having done it twice myself. As a fellow Texan, you will appreciate my funny RER story. I was sitting on the train waiting for it to depart when I couple boarded speaking Spanish to each other. I assumed they were from Spain until the man said to me in a strong Texas drawl, "is that an Aggie ring you're wearing?" Sure enough, a fellow Ag and not only that, we probably had partied together while at A&M (though too many beers and too many years prevented us from remembering each other). He was on the rugby team and I used to go to their parties. :-) Just goes to show that it truly IS a small world.