I thought Taylor was at at least 95% speed last year, and showed it on several plays. He rushed for over 1,000 yards and a 5.2 average, over 1,300 yards if you subtract the sacks he took on non-running plays. Even if you take him out of the run option game, he can still beat a lot of defenders to the stick when a pass play breaks down on 3rd and 9, and that is always a valuable weapon, whether or not you consider yourself a running quarterback.
I don't know if the coaches have been holding him back, or Taylor has been doing it himself, but it almost seems like they're determined to prove Taylor is passing threat, and he's been encouraged to stick with the pass play even as the pocket is collapsing and there's a gaping seam right up the middle.
He has definitely changed the way he allows himself to be tackled from his Freshman year, and it's just not a good look.