His success will largely depend on how much weight he is able to gain, but his upside is pretty good in an uptempo system with a pass first point guard.
Stevens not known for uptempo style offense, more of a half court guru. Wonder if he will figure out a way to take advantage of Zeller's ability to run the floor.
Actually, Danny said he was a good fit for Stevens' system as a 5 that would run the floor to the front of the rim. Stevens echoed that in his quotes on the acquisition
The primary passing goal of Steven's motion offense is to pass it into the post. So you want someone who can read weak side gaps to make a cut to the basket in rhythm with the offense (as well as run to the hoop on transition, as you indicate), with good hands and who can finish quickly. I think Zeller will work well in this regard. He gets his shot up quickly off the catch.
He's not that great of a self-point-creator, as his back-to-the-basket skills are not that strong yet, though he's not terrible and should improve with experience. I think Sully & Olynyk are both more skilled in that area.