Is the Roissy bus from the airport like a city transit? I didn't know if it would be difficult to carry luggage on it. Also, since it stops at the Place de Opera, is it convenient to walk from there to a hotel in that district instead of getting on the metro? Is the Air France shuttle any better or worse? Is it much better to take a pre-arranged airport-hotel shuttle, even though it is much more expensive? Thanks from a first time Paris visitor.