Checked baggage

That depends completely on how many other planes are arriving at the same time. I have had it take as much as an hour to get through the whole immigration/baggage process, but it can be quicker. Just no way to know.

There is no answer. It all depends - unfortunately on a lot of unpredictable events. Is there a reason for the question?

Yes. The reason is that I'm going form CDG to Paris Montparnasse to catch a 5:25pm train. The plane lands a 12:30 in the afternoon and I'm planning on taking the Air France shuttle bus to the station instead of the metro...which I hope is not a big difference in time there either. I know traffic is a possible problem but I heard also that the AF shuttle has a gps that tells them what roads to avoid that are jammed. So when I get to Paris, there is a site that I want to see that is about 2 miles tops from Montparnasse. I just was hoping to have enough time before the train to be at the site for a half an hr. Its also a Sunday though. And I have to validate my rail pass at Montparnasse and print out the ticket. Any suggestions? :)

What exactly is the sight "two miles from Montparnasse"? Depending on the particulars, it could take a LOT of time to reach from the station. If you tell us, people can give you better guidance about whether it's even worth attempting, or if you don't have any chance of seeing it and still making your train. Think of New York. If you were flying in to JFK and leaving from Penn Station a few hours later, would you try to see something two miles from Penn Station before catching your train? Particularly if you had non-refundable tickets, and it was your first visit so you didn't know your way around?

If things go well it's not impossible that you could be at Montparnasse by 2. That would give you time to hop the metro (or take a cab) and visit mystery site (if it is on the metro, if you have your ticket already, and if you have a plan for your bags). Problem is there is no guarantee. So I think you'll need plans A and B contingent on when you arrive.

It's just a church that I wanted to see and I found out that it's only one mile from Montparnasse...and I have a map and directions. Hopefully I'll make it.