From what I've read the new Canon has Vader more powerful in the Force. But that didn't mean he doesn't have certain speed/mobility issues in the suit.
The Rebels panel at SW Celebration said they could have made Vader super fast in animation but they decided that's not Vader. He's strong and powerful but not fast and mobile. At least that's the meaning I'm getting. So I still think ROTS Anakin takes Sabers.
I might be wrong though. Will see more evidence from the new canon.