I just noticed this thread. Well, the bench presses I build have safety rails. The purpose of them is to stop the weight from hitting the neck. So if a user can't lift the weight it settles on the safety rails and he can easily slide under the bar. We have safety bars on squat racks, Smith Machines, press behind the neck, incline and even decline benches. I have always built safety into my equipment.
The apparatus with hydraulic lowering bench is clever and many gyms will install them because of the safety factor. I wouldn't mind one for our gym.