The only people that will be using magnets effectively are the people that can build good enough robots to take the forces the magnets put on there own machine and the people that complain will be the ones that can't build a good enough machine. Robots have to evolve or it's going to get very boring. Say 540 wins the uk champs it then forces people to find a way to try beat a robot that effectively weighs 50kg once it's in the arena. Once you get under a robot with a magnet for every 1mm you get it's magnet away from the floor it dramatically reduces the pull the magnet has on the floor, if you manage to flip it upside down it's just a regular 13kg robot.