A picture is worth a thousand words, so the saying goes. I believe that; which is why when telling type rating candidates that reverse is more effective at high speed I use the following demo in the simulator.
For example: 737 Classic. Take off on slippery runway surface ice patches (input into simulator). Flaps One max structural weight with all engines abort at 150 knots on 10,000 ft runway sea level nil wind.
First abort using speed brake and brakes only. No reverse. Result was over-run the end at 30 knots.
Second abort: Full reverse at 150 knots. No brakes and no speed brake. Over-run about 30 knots as well.
Third abort: 150 knots Maximum manual braking. Speed brake and max reverse. Aircraft stops on runway about 300 metres from the end.
Conclusion: It was the full reverse (plus brakes and speed brake) that made the difference and permitted the aircraft to stop with room to spare.
Admitted freely that this was an amateur and unmeasured attempt to prove reverse at high speed is more effective for stopping than at low speed. Candidates were convinced.