An addage often quoted is "equipment is cheaper than employees." If that is true, why wouldn't we want the biggest deck and fastest mower out on our lawns??? If Z's are faster, which is true in regards to speed, why use walk behinds that don't move as fast? Turn around time? Is a Z slower turning around than a walk behind. I think the difference is negligible, and easily made up on the faster ground speed. If the users of walk behinds are utilizing them because of a lighter foot print, then I can understand that. But if the Z's move faster...and equipment is cheaper than employees...why do the big companies use walk behinds? Is this statement in accurate?