[Faith]

I think bumpers are better in most cases. They do add an extra 15lbs of weight. They also make it harder to injure your robot, which is always a plus. In some cases they may prevent climbing the ramp, however - they may also help climbing the ramp, making the robot less top-heavy. It all depends on the robot...

I guess defense it would be better to have bumpers for protection, weight, and traction.