Based off of his normal Bankai. Although his Hollow mask makes him stronger, he still couldn't completely control it. If you saw, he only had it on for about 6 seconds, before dispelling it. Methinks he still can't control it to make him much faster, at that point in the story.
Edit: Based on the filler, the guy heading the Zanpakto attack is named Muramasa.
http://en.wikipedia.org/wiki/Muramasa