Rollers.
Doesn't make them good ones either; they serve a very different purpose, and transport is way down the list.
But regarding the cameras - they are currently all flawed in one way or another. Was a time one could buy (and get!) pretty much anything off the shelf and it would do what it said on the box; then, final inspection became a step too expensive and the client took on the rôle, not that he knew that, of course.
The Bronica 100mm was reasonable; the worst of the three focal lengths I mentioned was the 50mm, which shouldn't really have surprised me. But even the body was flawed, and that was brand new, as were the optics: the MU did not function one single time.
Rob C