Too close.
Savard has been a long-time favourite; well, since I started to get some classic old games in the early '00s. He just had the poise and the ability to control the tempo of the game like not many others. For example, Brad Park may have been more efficient than Savard in the 1972 Series, but for my money, Savard was Canada's best Dman in most of the five games he played. And in spite of his reputation as a defensive defenseman, he could play some good offense too, even in his later years ("Too many men on the ice" game!). BTW, Savard's overall post-season PPG average is clearly higher than the regular season one.
Rod Langway is more of a mystery to me, even though when I've seen him, he has impressed me. However, it's hard to vote against him, because he has all that hardware/all-star selections over Savard (partly due to 'different climate' in the '80s, I'm sure), and because he somewhat made Washington Capitals, whereas Savard was just one of the key players on his team. Of course, they played a few seasons together on the Habs, but since they were in totally different stages of their careers, that comparison isn't particulary fruitful.