Yeah, but I think Vader has more raw power and a better ability to use it. In a contest between them of force-offensives (although I know that is not the only factor), I think Vader would win.
Fishy posted about two seconds before I did, so I will respond to his post (the last one was to Revan Darkstar). I think force-users can block force-offensives, but I think they can also be overcome if an opponent has superior Force power.
Vader's a better force user but not by much so it really doesn't matter. You have to have to be way stronger in the Force for it to make a difference and there isn't that much of a gap between Vader and Maul. Maul is a much better duelist so I would bet on him. I think Vader's only chance is outsmarting Maul, which would NOT be easy.