Sorry, I am not a Paris person. And no comments please on why I am flying to CDG. I don't do trains. I just don't. I do Club Europe instead.

So, arriving on Sunday, what's the best way into town? Staying near the Opera. How long will a taxi take, and approximate cost? The Roissybus seems to be every 15 mins and EUR8.60 each from T2B-2D door 11, T2A-2C door 9. Is it close, convenient, better than a cab? Or how easy is it to get to the RER line B?